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
= 18 ÷ 2
= 9 cm
Radius of the large quarter circle
= 18 + 9
= 27 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 27
= 42.39 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 18
= 28.26 cm
Perimeter of the shaded figure
= 2 x 42.39 + 3 x 28.26 + 2 x 9 + 18
= 84.78 + 84.78 + 36
= 205.56 cm
Answer(s): (a) 27 cm; (b) 205.56 cm