In the figure given in the problem, calculate the length of an edge.

A triangle has been drawn inside this circle. Can you find the length of the chord it forms?

What is the area of the region common to this triangle and square?

The perimeter of a large triangle is 24 cm. What is the total length of the black lines used to draw the figure?

A garden has the shape of a right-angled triangle. A fence goes from the corner with the right-angle to a point on the opposite side. How long is the fence?

An isosceles triangle is drawn inside another triangle. Can you work out the length of its base?

Use facts about the angle bisectors of this triangle to work out another internal angle.

How does the perimeter change when we fold this isosceles triangle in half?

The diagram shows a quadrilateral ABCD, in which AD=BC, ∠CAD=50∘, ∠ACD=65∘ and ∠ACB=70∘. What is the size of ∠ABC?

The diagram shows an equilateral triangle touching two straight lines. What is the sum of the four marked angles?