The figure is made up of identical quadrants. The radius is 47 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 47 x 47
= 6936.26 cm
2 Area of
12 shaded leaf
= (6936.26 ÷ 4) - (
12 x 47 x 47)
= 629.565 cm
2 Area of four
12 shaded leaf
= 629.565 x 4
= 2518.26 cm
2 Area of the shaded part
= 6936.26 + 2518.26
= 9454.52 cm
2 (b)
Length of combined curved lines
= 3.14 x 47 x 2 x 2
= 590.32 cm
Length of 12 straight lines
= 47 x 12
= 564 cm
Perimeter of the shaded part
= 590.32 + 564
= 1154.32 cm
Answer(s): (a) 9454.52 cm
2; (b) 1154.32 cm