WAEC - Mathematics (1993 - No. 18)
The angle of a sector of a circle radius 10.5cm is 120°. Find the perimeter of the sector [Take π = 22/7]
22cm
33.5cm
43cm
66cm
115.5cm
Explicació
Perimeter of a sector = \(2r + \frac{\theta}{360} \times 2\pi r\)
= \(2(10.5) + \frac{120}{360} \times 2 \times \frac{22}{7} \times 10.5\)
= \(21 + 22\)
= 43 cm