Question

The diagram shows 15 identical circles, arranged as a rectangle, and a shaded triangle. The verticices of the triangle are at the centre of circles calculate the area of the shaded triangle.

Answer 1

To find the area of the triangle, you will need to know the length of the base and there length of the height.

You can find both of these by using the circles that are given.

If the total length of the circles is 35 cm, then each circle has a length of 7 cm. If these are circles, then each circle has a height of 7 cm also.

A = 1/2 x b x h
1/2 x (4x7) x (2x7)
A = 196 square cm