Hi,

This is rather confusing as the only measurement given is 12cm. Need help to explain how to solve this.

Thank you.

Hi,

This is rather confusing as the only measurement given is 12cm. Need help to explain how to solve this.

Thank you.

waterflow

(a) perimeter of figure 1 = 3/4 of circle perimeter + 2 * radius

perimeter of figure 2 = 3/4 of circle perimeter + 4 * radius

Note : 4 radius for figure 2 because there are 2 radius on both ends, at the centre, the straight line is divided into 3 equal parts and each part is half radius, so 4 of them give another 2 radius.

So difference in perimeter between figure 2 and figure 1 = 2 * radius = 12 cm

radius = 6cm

Perimetr of figure 1 = 3 * 2 * 3.14 * 6/4 + 2 * 6 cm = 28.26 + 6 cm = 34.26 cm

(b) Area of figure 2 = 3/4 of area of circle = 3 * 3.14 * (6)²/4 = 84.78 cm²