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
= 7 ÷ 2
= 3.5 cm
Radius of the large quarter circle
= 7 + 3.5
= 10.5 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 10.5
= 16.485 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 7
= 10.99 cm
Perimeter of the shaded figure
= 2 x 16.485 + 3 x 10.99 + 2 x 3.5 + 7
= 32.97 + 32.97 + 14
= 79.94 cm
Answer(s): (a) 10.5 cm; (b) 79.94 cm