PSLE The outline of the shaded figure is formed by 3 identical small quarter circles, 2 identical large quarter circles and 3 straight lines. Take π = 3.14
- What is the radius of the large quarter circle?
- Find the perimeter of the shaded figure.
(a)
Length of AB
= Length of BC
= 8 ÷ 2
= 4 cm
Radius of the large quarter circle
= 8 + 4
= 12 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 12
= 18.84 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 8
= 12.56 cm
Perimeter of the shaded figure
= 2 x 18.84 + 3 x 12.56 + 2 x 4 + 8
= 37.68 + 37.68 + 16
= 91.36 cm
Answer(s): (a) 12 cm; (b) 91.36 cm