Higher November 2018 Paper 5 Q17

OCRHigherCurrent spec4 marksSimilar Shapes

17 The diagram consists of three mathematically similar shapes.
The heights of the shapes are in the ratio 1 : 4 : 5.

Three similar cross shapes one inside another: the smallest (unshaded) inside the middle one (shaded), inside the largest (unshaded border)

Not to scale

Find the ratio

total shaded area : total unshaded area.

Give your answer in its simplest form. [4]