List

Angles, Polygons and Geometrical Proof Short Problems

This is part of our collection of Short Problems.

You may also be interested in our longer problems on Angles, Polygons and Geometrical Proof Age 11-14 and Age 14-16.

Printable worksheets containing selections of these problems are available here:

Stage 3 ★ Sheet 1 Solutions
  Sheet 2 Solutions
  Sheet 3 Solutions
  Sheet 4 Solutions
     
Stage 3 ★★ Sheet 1 Solutions
  Sheet 2 Solutions
  Sheet 3 Solutions
     
Stage 4 ★★ Sheet 1 Solutions
  Sheet 2 Solutions
     
Stage 4 ★★★ Sheet 1 Solutions
Angular Reflection
problem

Angular Reflection

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 28 - 2013
Two lines meet at a point. Another line through this point is reflected in both of these lines. What is the angle between the image lines?
Diagonal Division
problem

Diagonal Division

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 45 - 2008
The diagram shows a regular pentagon with two of its diagonals. If all the diagonals are drawn in, into how many areas will the pentagon be divided?
Stellar Angles
problem

Stellar Angles

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 30 - 2013
What is the angle $x$ in the star shape shown?
Overlapping beer mats
problem

Overlapping beer mats

Age
11 to 14
Challenge level
filled star empty star empty star
Can you find the area of the overlap when these two beer mats are placed on top of each other?
As Long as Possible
problem

As Long as Possible

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 40 - 2013
Given three sides of a quadrilateral, what is the longest that the fourth side can be?
Bishop's Paradise
problem

Bishop's Paradise

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 37 - 2013
Which of the statements about diagonals of polygons is false?
Half Past Two
problem

Half Past Two

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 21 - 2009
What is the angle between the two hands of a clock at 2.30?
Central Distance
problem

Central Distance

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 1 - 2006
The diagram shows two circles enclosed in a rectangle. What is the distance between the centres of the circles?
Right-Angled Request
problem

Right-Angled Request

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 26 - 2006
How many right angled triangles are formed by the points in this diagram?
Two Exterior Triangles
problem

Two Exterior Triangles

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 35 - 2009
Two equilateral triangles have been drawn on two adjacent sides of a square. What is the angle between the triangles?
Distinct Diagonals
problem

Distinct Diagonals

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 21 - 2010
How many diagonals can you draw on this square...
Robo-Turn
problem

Robo-Turn

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 16 - 2007
Can you figure out how far the robot has travelled by the time it is first facing due East?
Angle Hunt
problem

Angle Hunt

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 39 - 2010
If you know three lengths and an angle in this diagram, can you find another angle by calculation?
Polygon Cradle
problem

Polygon Cradle

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 18 - 2007
A regular pentagon together with three sides of a regular hexagon form a cradle. What is the size of one of the angles?
Outside the Nonagon
problem

Outside the Nonagon

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 44 - 2010
Extend two of the sides of a nonagon to form an angle. How large is this acute angle?
Angle of Overlap
problem

Angle of Overlap

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 26 - 2007
The diagram shows two equilateral triangles. What is the value of x?
Homely Angles
problem

Homely Angles

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 18 - 2011
Draw an equilateral triangle onto one side of a square. Can you work out one particular angle?
Square Bisection
problem

Square Bisection

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 8 - 2008
In how many ways can a square be cut in half using a single straight line cut?
Regular Vertex
problem

Regular Vertex

Age
11 to 14
Challenge level
filled star empty star empty star
A square, regular pentagon and equilateral triangle share a vertex. What is the size of the other angle?
Tent Poles
problem

Tent Poles

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 40 - 2015
In the diagram, $PT = QT = TS$ and $QS = SR$. What is the value of $x$?
Parallel Base
problem

Parallel Base

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 46 - 2015
The diagram shows two parallel lines and two angles. What is the value of x?
Other Side
problem

Other Side

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 8 - 2016
Can you work out the size of the angles in a quadrilateral?
Triangle in a Corner
problem

Triangle in a Corner

Age
11 to 14
Challenge level
filled star empty star empty star
The diagram shows an equilateral triangle touching two straight lines. What is the sum of the four marked angles?
Isometric Rhombuses
problem

Isometric Rhombuses

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 31 - 2016
The diagram shows a grid of $16$ identical equilateral triangles. How many rhombuses are there made up of two adjacent small triangles?
Equilateral Pair
problem

Equilateral Pair

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 39 - 2016
In the diagram, VWX and XYZ are congruent equilateral triangles. What is the size of angle VWY?
Isosceles Meld
problem

Isosceles Meld

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 9 - 2012
What is the angle QPT in this diagram?
Stacking Shapes
problem

Stacking Shapes

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 28 - 2017
The diagram on the right shows an equilateral triangle, a square and a regular pentagon. What is the sum of the interior angles of the resulting polygon?
Long Shadows
problem

Long Shadows

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 10 - 2012
If you know how long Meg's shadow is, can you work out how long the shadow is when she stands on her brother's shoulders?
Angle Please
problem

Angle Please

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 19 - 2017
In the figure, what is the value of x?
Shared Vertex
problem

Shared Vertex

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 38 - 2017
In the diagram, what is the value of $x$?
Descending Angles
problem

Descending Angles

Age
11 to 14
Challenge level
filled star filled star empty star
Given four of the angles in two triangles, can you find the smallest angle overall?
Triangle Split
problem

Triangle Split

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 50 - 2008
The lengths SP, SQ and SR are equal and the angle SRQ is x degrees. What is the size of angle PQR?
Rectangle Dissection
problem

Rectangle Dissection

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 2 - 2009
The 16 by 9 rectangle is cut as shown. Rearrange the pieces to form a square. What is the perimeter of the square?
Two Triangles
problem

Two Triangles

Age
11 to 14
Challenge level
filled star filled star empty star
Prove that the angle marked $a$ is half the size of the angle marked $b$.
Square in a Triangle
problem

Square in a Triangle

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 33 - 2006
A square is inscribed in an isoscles right angled triangle of area $x$. What is the area of the square?
Placeholder: several colourful numbers
problem

Perimeter Puzzle

Age
11 to 14
Challenge level
filled star filled star empty star
If four copies of this triangle are joined together to form a parallelogram, what is the largest possible perimeter of the parallelogram?
Placeholder: several colourful numbers
problem

Diagonal Side

Age
11 to 14
Challenge level
filled star filled star empty star
Can you work out the area of a square drawn on a diagonal?
Fangs
problem

Fangs

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 7 - 2013
Three of the angles in this diagram all have size $x$. What is the value of $x$?
Six Minutes Past Eight
problem

Six Minutes Past Eight

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 45 - 2007
What is the obtuse angle between the hands of a clock at 6 minutes past 8 o'clock?
Inscribed Hexagon
problem

Inscribed Hexagon

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 1 - 2014
The diagram shows a regular hexagon inside a rectangle. What is the sum of the four marked angles?
Hexapentagon
problem

Hexapentagon

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 53 - 2007
The diagram shows a regular pentagon and regular hexagon which overlap. What is the value of x?
Extended Parallelogram
problem

Extended Parallelogram

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 11 - 2014
The diagram shows a parallelogram and an isosceles triangle. What is the size of angle TQR?
Rhombus Diagonal
problem

Rhombus Diagonal

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 19 - 2014
The diagram shows a rhombus and an isosceles triangle. Can you work out the size of the angle JFI?
Outside the Boxes
problem

Outside the Boxes

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 13 - 2008
The diagram shows three squares drawn on the sides of a triangle. What is the sum of the three marked angles?
Radioactive Triangle
problem

Radioactive Triangle

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 41 - 2014
Three straight lines divide an equilateral triangle into seven regions. What is the side length of the original triangle?
U in a Pentagon
problem

U in a Pentagon

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 18 - 2008
The diagram shows a regular pentagon. Can you work out the size of the marked angle?
Right Angled Octagon
problem

Right Angled Octagon

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 38 - 2008
A quadrilateral can have four right angles. What is the largest number of right angles an octagon can have?
Handy Angles
problem

Handy Angles

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 39 - 2008
How big is the angle between the hour hand and the minute hand of a clock at twenty to five?
Adding Angles
problem

Adding Angles

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 47 - 2016
What is the sum of the six marked angles?
Nonagon Angle
problem

Nonagon Angle

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 53 - 2012
ABCDEFGHI is a regular nine-sided polygon (called a 'nonagon' or 'enneagon'). What is the size of the angle FAE ?
Placeholder: several colourful numbers
problem

Triangle in the corner

Age
11 to 14
Challenge level
filled star filled star empty star
A triangle is shaded within a regular hexagon. Can you find its area?
Integral Polygons
problem

Integral Polygons

Age
11 to 14
Challenge level
filled star filled star empty star
Each interior angle of a particular polygon is an obtuse angle which is a whole number of degrees. What is the greatest number of sides the polygon could have?
Placeholder: several colourful numbers
problem

Funky Hexagon

Age
11 to 14
Challenge level
filled star filled star empty star
Can you find the value of x in this diagram?
Dodecagon Angles
problem

Dodecagon Angles

Age
11 to 14
Challenge level
filled star filled star empty star
Weekly Problem 50 - 2012
The diagram shows a regular dodecagon. What is the size of the marked angle?
Placeholder: several colourful numbers
problem

Perimeter in a Hexagon

Age
11 to 14
Challenge level
filled star filled star empty star
Can you find the perimeter of this triangle inscribed in a hexagon?
Placeholder: several colourful numbers
problem

Tricky Tessellations

Age
11 to 14
Challenge level
filled star filled star empty star
Can you work out the fraction of the tiles that are painted black in this pattern?
Equal Lengths
problem

Equal Lengths

Age
11 to 14
Challenge level
filled star filled star filled star
Weekly Problem 29 - 2013
An equilateral triangle is drawn inside a rhombus, both with equal side lengths. What is one of the angles of the rhombus?
Clock Face Angles
problem

Clock Face Angles

Age
11 to 14
Challenge level
filled star filled star filled star
The time is 20:14. What is the smaller angle between the hour hand and the minute hand on an accurate analogue clock?
Clock angle
problem

Clock angle

Age
11 to 14
Challenge level
filled star filled star filled star
What is the angle between the the hands of a clock at 8:24?
Overbearing
problem

Overbearing

Age
11 to 14
Challenge level
filled star filled star filled star
A village has a pub, church and school. What is the bearing of the school from the church?
inner rectangle
problem

inner rectangle

Age
11 to 14
Challenge level
filled star filled star filled star
If the shape on the inside is a rectangle, what can you say about the shape on the outside?
No rights
problem

No rights

Age
11 to 14
Challenge level
filled star filled star filled star
Prove that the angle bisectors of a triangle can never meet at right angles.
Placeholder: several colourful numbers
problem

Add all the angles

Age
11 to 14
Challenge level
filled star filled star filled star
Find the sum of all of the angles denoted by letters in this diagram
Trapezium Arch
problem

Trapezium Arch

Age
11 to 14
Challenge level
filled star filled star filled star
Weekly Problem 27 - 2007
Ten stones form an arch. What is the size of the smallest angles of the trapezoidal stones?
Pentagon Ring
problem

Pentagon Ring

Age
11 to 14
Challenge level
filled star filled star filled star
Weekly Problem 47 - 2011
Place equal, regular pentagons together to form a ring. How many pentagons will be needed?
Heptagon Has
problem

Heptagon Has

Age
11 to 14
Challenge level
filled star filled star filled star
Weekly Problem 15 - 2012
How many of the five properties can a heptagon have?
Two Isosceles
problem

Two Isosceles

Age
11 to 14
Challenge level
filled star filled star filled star
Weekly Problem 37 - 2017
A quadrilateral is divided into two isosceles triangles. Can you work out the perimeter of the quadrilateral?
Hexagon Cut Out
problem

Hexagon Cut Out

Age
11 to 14
Challenge level
filled star filled star filled star
Weekly Problem 52 - 2012
An irregular hexagon can be made by cutting the corners off an equilateral triangle. How can an identical hexagon be made by cutting the corners off a different equilateral triangle?
Parallelogram in the Middle
problem

Parallelogram in the Middle

Age
11 to 14
Challenge level
filled star filled star filled star
Weekly Problem 27 - 2013
The diagram shows a parallelogram inside a triangle. What is the value of $x$?
Eulerian
problem

Eulerian

Age
14 to 16
Challenge level
filled star empty star empty star
Weekly Problem 37 - 2014
Which of the five diagrams below could be drawn without taking the pen off the page and without drawing along a line already drawn?
Centred
problem

Centred

Age
14 to 16
Challenge level
filled star empty star empty star
Weekly Problem 13 - 2012
The diagram shows contains some equal lengths. Can you work out one of the angles?
Placeholder: several colourful numbers
problem

Cat on a wall

Age
14 to 16
Challenge level
filled star empty star empty star
How high is the wall that this cat is lying on?
Internal - External
problem

Internal - External

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 12 - 2016
The diagram shows a square PQRS and two equilateral triangles RSU and PST. PQ has length 1. What is the length of TU?
Shaded Square
problem

Shaded Square

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 41 - 2016
The diagram shows a square, with lines drawn from its centre. What is the shaded area?
Inscribed Semicircle
problem

Inscribed Semicircle

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 43 - 2017
The diagram shows a semicircle inscribed in a right angled triangle. What is the radius of the semicircle?
Placeholder: several colourful numbers
problem

Octagonal Ratio

Age
14 to 16
Challenge level
filled star filled star empty star
Can you find the ratio of the area shaded in this regular octagon to the unshaded area?
Placeholder: several colourful numbers
problem

Block Challenge

Age
14 to 16
Challenge level
filled star filled star empty star
Can you work out the shaded area in this shape?
3-4-5 circle
problem

3-4-5 circle

Age
14 to 16
Challenge level
filled star filled star empty star
Can you find the radius of the circle inscribed inside a '3-4-5 triangle'?
Slide height
problem

Slide height

Age
14 to 16
Challenge level
filled star filled star empty star
How high is the top of the slide?
Placeholder: several colourful numbers
problem

Tunnel Vision

Age
14 to 16
Challenge level
filled star filled star empty star
How wide is this tunnel?
Placeholder: several colourful numbers
problem

Square and triangle

Age
14 to 16
Challenge level
filled star filled star empty star
Can you find the area of the yellow square?
Placeholder: several colourful numbers
problem

Doubly isosceles

Age
14 to 16
Challenge level
filled star filled star empty star
Find the missing distance in this diagram with two isosceles triangles
Tied up
problem

Tied up

Age
14 to 16
Challenge level
filled star filled star empty star
How much of the field can the animals graze?
Diagonal Touch
problem

Diagonal Touch

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 21 - 2012
Two rectangles are drawn in a rectangle. What fraction of the rectangle is shaded?
Two Right Angles
problem

Two Right Angles

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 4 - 2008
In the figure given in the problem, calculate the length of an edge.
Angle to Chord
problem

Angle to Chord

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 23 - 2008
A triangle has been drawn inside this circle. Can you find the length of the chord it forms?
Isosceles Reduction
problem

Isosceles Reduction

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 29 - 2010
An isosceles triangle is drawn inside another triangle. Can you work out the length of its base?
Incentre Angle
problem

Incentre Angle

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 1 - 2011
Use facts about the angle bisectors of this triangle to work out another internal angle.
Quarters
problem

Quarters

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 27 - 2014
Four congruent isosceles trapezia are placed in a square. What fraction of the square is shaded?
Cut-Up Square
problem

Cut-Up Square

Age
14 to 16
Challenge level
filled star filled star filled star
Weekly Problem 15 - 2015
In the diagram, two lines have been drawn in a square. What is the ratio of the areas marked?
Placeholder: several colourful numbers
problem

Overlapping Annuli

Age
14 to 16
Challenge level
filled star filled star filled star
Just from the diagram, can you work out the radius of the smaller circles?
Placeholder: several colourful numbers
problem

Circled Square

Age
14 to 16
Challenge level
filled star filled star filled star
Can you find the area of this square inside a circle?
Placeholder: several colourful numbers
problem

Height and Sides

Age
14 to 16
Challenge level
filled star filled star filled star
Can you find the area of the triangle from its height and two sides?
Placeholder: several colourful numbers
problem

Circular Inscription

Age
14 to 16
Challenge level
filled star filled star filled star
In the diagram, the radius of the circle is equal to the length AB. Can you find the size of angle ACB?
Placeholder: several colourful numbers
problem

Triangular intersection

Age
14 to 16
Challenge level
filled star filled star filled star
What is the largest number of intersection points that a triangle and a quadrilateral can have?