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
= 6 ÷ 2
= 3 cm
Radius of the large quarter circle
= 6 + 3
= 9 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 9
= 14.13 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 6
= 9.42 cm
Perimeter of the shaded figure
= 2 x 14.13 + 3 x 9.42 + 2 x 3 + 6
= 28.26 + 28.26 + 12
= 68.52 cm
Answer(s): (a) 9 cm; (b) 68.52 cm