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
= 10 ÷ 2
= 5 cm
Radius of the large quarter circle
= 10 + 5
= 15 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 15
= 23.55 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 10
= 15.7 cm
Perimeter of the shaded figure
= 2 x 23.55 + 3 x 15.7 + 2 x 5 + 10
= 47.1 + 47.1 + 20
= 114.2 cm
Answer(s): (a) 15 cm; (b) 114.2 cm