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
= 5 ÷ 2
= 2.5 cm
Radius of the large quarter circle
= 5 + 2.5
= 7.5 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 7.5
= 11.775 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 5
= 7.85 cm
Perimeter of the shaded figure
= 2 x 11.775 + 3 x 7.85 + 2 x 2.5 + 5
= 23.55 + 23.55 + 10
= 57.1 cm
Answer(s): (a) 7.5 cm; (b) 57.1 cm