The figure shows one big quadrant and two small semicircles. The radius of the big quadrant is 30 cm.
- Find the perimeter of the shaded figure. (Take π = 3.14)
- Find the shaded area of this figure. (Take π = 3.14)
(a)
Circumference of the small circle
= 3.14 x 30
= 94.2 cm
Diameter of the big quadrant
= 30 x 2
= 60 cm
Circumference of the big quadrant
= 3.14 x 60 x
14= 47.1 cm
Perimeter of the shaded figure
= 94.2 + 47.1
= 141.3 cm
(b)
Area of the big quadrant
= 3.14 x 30 x 30 x
14 = 706.5 cm
2 Area of the triangle
=
12 x 30 x 30
= 450 cm
2 Area of shaded area
= 706.5 - 450
= 256.5 cm
2 Answer(s): (a) 141.3 cm; (b) 256.5 cm
2