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
= 11 ÷ 2
= 5.5 cm
Radius of the large quarter circle
= 11 + 5.5
= 16.5 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 16.5
= 25.905 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 11
= 17.27 cm
Perimeter of the shaded figure
= 2 x 25.905 + 3 x 17.27 + 2 x 5.5 + 11
= 51.81 + 51.81 + 22
= 125.62 cm
Answer(s): (a) 16.5 cm; (b) 125.62 cm