waecmaths question:
The diagram shows an arc MN of a circle centre O, with radius 10cm, If $\angle MON={{72}^{\circ }}$ Calculate the length of the arc, correct to three significant figures. [Take $\pi =\tfrac{22}{7}$]
Option A:
6.28cm
Option B:
12.6cm
Option C:
22.6cm
Option D:
62.8cm
waecmaths solution:
$length\text{ }of\text{ }arc=\frac{\theta }{{{360}^{\circ }}}\times 2\pi r=\frac{{{72}^{{}^\circ }}}{{{360}^{{}^\circ }}}\times 2\times \frac{22}{7}\times 10=12.57cm\simeq 12.6cm$
maths year:
maths topics: