The angle of a sector of s circle, radius 10.5cm, is 48°, Calculate the perimeter of the sector

  • A 8.8cm
  • B 25.4cm
  • C 25.6cm
  • D 29.8cm
jamb 1990mathematics

The correct answer is D. 29.8cm

Length of Arc AB = \(\frac{\theta}{360}\) 2\(\pi\)r 

= \(\frac{48}{360}\) x 2\(\frac{22}{7}\) x \(\frac{21}{2}\) 

= \(\frac{4 \times 22 \times \times 3}{30}\) \(\frac{88}{10}\) 

= 8.8cm Perimeter = 8.8 + 2r = 8.8 + 2(10.5) = 8.8 + 21 = 29.8cm

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