The figure shows one big quadrant and two small semicircles. The radius of the big quadrant is 40 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 40
= 125.6 cm
Diameter of the big quadrant
= 40 x 2
= 80 cm
Circumference of the big quadrant
= 3.14 x 80 x
14= 62.8 cm
Perimeter of the shaded figure
= 125.6 + 62.8
= 188.4 cm
(b)
Area of the big quadrant
= 3.14 x 40 x 40 x
14 = 1256 cm
2 Area of the triangle
=
12 x 40 x 40
= 800 cm
2 Area of shaded area
= 1256 - 800
= 456 cm
2 Answer(s): (a) 188.4 cm; (b) 456 cm
2