Triangles

There are 116 NRICH Mathematical resources connected to Triangles
LOGO Challenge 5 - Patch
problem

LOGO Challenge 5 - Patch

Age
11 to 16
Challenge level
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Using LOGO, can you construct elegant procedures that will draw this family of 'floor coverings'?
Rectangle Tangle
problem

Rectangle Tangle

Age
7 to 11
Challenge level
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The large rectangle is divided into a series of smaller quadrilaterals and triangles. Can you untangle what fractional part is represented by each of the shapes?
Tri-Five
problem

Tri-Five

Age
7 to 11
Challenge level
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Find all the different shapes that can be made by joining five equilateral triangles edge to edge.
Six to Four
problem

Six to Four

Age
5 to 7
Challenge level
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Move four sticks so there are exactly four triangles.
Egyptian Rope
problem

Egyptian Rope

Age
7 to 11
Challenge level
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The ancient Egyptians were said to make right-angled triangles using a rope with twelve equal sections divided by knots. What other triangles could you make if you had a rope like this?
Triangular Tantaliser
problem

Triangular Tantaliser

Age
11 to 14
Challenge level
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Draw all the possible distinct triangles on a 4 x 4 dotty grid. Convince me that you have all possible triangles.
Are you kidding
problem

Are you kidding

Age
14 to 16
Challenge level
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If the altitude of an isosceles triangle is 8 units and the perimeter of the triangle is 32 units.... What is the area of the triangle?
Lens Angle
problem

Lens Angle

Age
14 to 16
Challenge level
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Find the missing angle between the two secants to the circle when the two angles at the centre subtended by the arcs created by the intersections of the secants and the circle are 50 and 120 degrees.
Counting Triangles
problem

Counting Triangles

Age
11 to 14
Challenge level
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Triangles are formed by joining the vertices of a skeletal cube. How many different types of triangle are there? How many triangles altogether?
Tricircle
problem

Tricircle

Age
14 to 16
Challenge level
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The centre of the larger circle is at the midpoint of one side of an equilateral triangle and the circle touches the other two sides of the triangle. A smaller circle touches the larger circle and two sides of the triangle. If the small circle has radius 1 unit find the radius of the larger circle.