Question

How do i work it out

Answer 1

15 cm

Explanation:

we know the rectangles are 5 by 1 cm so looking at the length of the shaded area it’s the same length as a rectangle which is 5cm

the width is the length of a rectangle subtracted by 2 width of other triangle which is 3 cm

So we jus multiply 3 and 5 which is 15 cm