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
= 28 ÷ 2
= 14 cm
Radius of the large quarter circle
= 28 + 14
= 42 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 42
= 65.94 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 28
= 43.96 cm
Perimeter of the shaded figure
= 2 x 65.94 + 3 x 43.96 + 2 x 14 + 28
= 131.88 + 131.88 + 56
= 319.76 cm
Answer(s): (a) 42 cm; (b) 319.76 cm