Length of rectangle
= 3 diameter of circle + 2 radii of circle
= 3 diameter + 1 diameter
= 4 diameter

Width of rectangle
= 1 diameter of circle + 2 radii of circle
= 2 diameter

Ratio of length of width = 4 : 2
= 2 : 1

So length = 2 unit, width = 1 unit

Area = 2 units x 1 unit = 2 x 1 unit x 1 unit

2 x 1 unit x 1 unit = 288cm²

1 unit x 1 unit = 288cm² ÷ 2 = 144cm²

1 unit x 1 unit = 12cm x 12cm

So 1 unit = 12cm

Perimeter = 2 lengths + 2 widths
= 1 unit x 2 + 2 units x 2
= 2 units + 4 units
= 6 units
= 6 x 12cm
= 72cm


b)

Width = 2 diameter = 1 unit = 12cm
1 diameter = 12cm ÷ 2 = 6cm

1 radius = 6 cm ÷ 2 = 3cm

If you pair up all the semicircles and join the quarter circles together , you can form 7 whole circles.


Area of these 7 circles

= 7 x π x radius x radius

= 7 x 22/7 x 3cm x 3cm

= 22 x 9cm²

= 198 cm²


Total area of figure

= 198cm² + 288cm²
= 486cm²