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
= 14 ÷ 2
= 7 cm
Radius of the large quarter circle
= 14 + 7
= 21 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 21
= 32.97 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 14
= 21.98 cm
Perimeter of the shaded figure
= 2 x 32.97 + 3 x 21.98 + 2 x 7 + 14
= 65.94 + 65.94 + 28
= 159.88 cm
Answer(s): (a) 21 cm; (b) 159.88 cm