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
= 19 ÷ 2
= 9.5 cm
Radius of the large quarter circle
= 19 + 9.5
= 28.5 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 28.5
= 44.745 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 19
= 29.83 cm
Perimeter of the shaded figure
= 2 x 44.745 + 3 x 29.83 + 2 x 9.5 + 19
= 89.49 + 89.49 + 38
= 216.98 cm
Answer(s): (a) 28.5 cm; (b) 216.98 cm