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
= 3 ÷ 2
= 1.5 cm
Radius of the large quarter circle
= 3 + 1.5
= 4.5 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 4.5
= 7.065 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 3
= 4.71 cm
Perimeter of the shaded figure
= 2 x 7.065 + 3 x 4.71 + 2 x 1.5 + 3
= 14.13 + 14.13 + 6
= 34.26 cm
Answer(s): (a) 4.5 cm; (b) 34.26 cm