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
= 23 ÷ 2
= 11.5 cm
Radius of the large quarter circle
= 23 + 11.5
= 34.5 cm
(b)
Circumference of each large quarter
=
14 x 2 x 3.14 x 34.5
= 54.165 cm
Circumference of each small quarter circle
=
14 x 2 x 3.14 x 23
= 36.11 cm
Perimeter of the shaded figure
= 2 x 54.165 + 3 x 36.11 + 2 x 11.5 + 23
= 108.33 + 108.33 + 46
= 262.66 cm
Answer(s): (a) 34.5 cm; (b) 262.66 cm