The figure is made up of identical quadrants. The radius is 19 cm long. Take π as 3.14.
- Find the area of the shaded part.
- Find the perimeter of the shaded part.
(a)
Area of one circle
= 3.14 x 19 x 19
= 1133.54 cm
2 Area of
12 shaded leaf
= (1133.54 ÷ 4) - (
12 x 19 x 19)
= 102.885 cm
2 Area of four
12 shaded leaf
= 102.885 x 4
= 411.54 cm
2 Area of the shaded part
= 1133.54 + 411.54
= 1545.08 cm
2 (b)
Length of combined curved lines
= 3.14 x 19 x 2 x 2
= 238.64 cm
Length of 12 straight lines
= 19 x 12
= 228 cm
Perimeter of the shaded part
= 238.64 + 228
= 466.64 cm
Answer(s): (a) 1545.08 cm
2; (b) 466.64 cm