2D shapes and their properties

There are 152 NRICH Mathematical resources connected to 2D shapes and their properties
Lawnmower
problem

Lawnmower

Age
14 to 16
Challenge level
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A kite shaped lawn consists of an equilateral triangle ABC of side 130 feet and an isosceles triangle BCD in which BD and CD are of length 169 feet. A gardener has a motor mower which cuts strips of grass exactly one foot wide and wishes to cut the entire lawn in parallel strips. What is the minimum number of strips the gardener must mow?
Lying and Cheating
problem

Lying and cheating

Age
11 to 14
Challenge level
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Follow the instructions and you can take a rectangle, cut it into 4 pieces, discard two small triangles, put together the remaining two pieces and end up with a rectangle the same size. Try it!
Same Shapes
problem

Same shapes

Age
5 to 7
Challenge level
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How can these shapes be cut in half to make two shapes the same shape and size? Can you find more than one way to do it?
Efficient packing
problem

Efficient packing

Age
14 to 16
Challenge level
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How efficiently can you pack together disks?
2D-3D
problem

2d-3d

Age
16 to 18
Challenge level
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Two circles of equal size intersect and the centre of each circle is on the circumference of the other. What is the area of the intersection? Now imagine that the diagram represents two spheres of equal volume with the centre of each sphere on the surface of the other. What is the volume of intersection?
Holly
problem

Holly

Age
14 to 16
Challenge level
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The ten arcs forming the edges of the "holly leaf" are all arcs of circles of radius 1 cm. Find the length of the perimeter of the holly leaf and the area of its surface.
Diagonal Division
problem

Diagonal division

Age
11 to 14
Challenge level
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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?
The medieval octagon
problem

The medieval octagon

Age
14 to 16
Challenge level
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Medieval stonemasons used a method to construct octagons using ruler and compasses... Is the octagon regular? Proof please.
LOGO Challenge 10 - Circles
problem

Logo challenge 10 - circles

Age
11 to 16
Challenge level
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In LOGO circles can be described in terms of polygons with an infinite (in this case large number) of sides - investigate this definition further.
Making Shapes
problem

Making shapes

Age
5 to 7
Challenge level
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Arrange any number of counters from these 18 on the grid to make a rectangle. What numbers of counters make rectangles? How many different rectangles can you make with each number of counters?