Find the angle at which an arc of length 22 cm subtends at the centre of a circle of radius 15cm. [Take \(\pi = \frac{22}{7}\)]

  • A 70\(^o\)
  • B 84\(^o\)
  • C 96\(^o\)
  • D 156\(^o\)
waec 2019mathematics

The correct answer is B. 84\(^o\)

L = \(\frac{\theta}{360} \times 2 \pi r\)

22 = \(\frac{theta}{360} \times 2 \times \frac{22}{7} \times 15\)

\(\theta = \frac{22 \times 360 \times 7}{2 \times 22 \times 15}\)

\(\theta\) = 84\(^o\)

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