WAEC - Mathematics (1994 - No. 30)
Calculate, correct to 2 significant figures, the length of the arc of a circle of radius 3.5cm which subtends an angle of 75° at the centre of the circle. [Take π = 22/7].
2.3cm
4.6cm
8cm
16cm
110cm
Wyjaśnienie
Length of arc = \(\frac{\theta}{360} \times 2\pi r\)
= \(\frac{75}{360} \times 2 \times \frac{22}{7} \times 3.5\)
= \(4.583 cm\)
\(\approxeq\) 4.6 cm (to 2 sig. figs)