The figure is made up of identical quadrants. The radius is 38 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 38 x 38
= 4534.16 cm
2 Area of
12 shaded leaf
= (4534.16 ÷ 4) - (
12 x 38 x 38)
= 411.54 cm
2 Area of four
12 shaded leaf
= 411.54 x 4
= 1646.16 cm
2 Area of the shaded part
= 4534.16 + 1646.16
= 6180.32 cm
2 (b)
Length of combined curved lines
= 3.14 x 38 x 2 x 2
= 477.28 cm
Length of 12 straight lines
= 38 x 12
= 456 cm
Perimeter of the shaded part
= 477.28 + 456
= 933.28 cm
Answer(s): (a) 6180.32 cm
2; (b) 933.28 cm