A chord subtends an angle of 120o at the centre of a circle of radius...

WAEC 2014

A chord subtends an angle of 120^o at the centre of a circle of radius 3.5cm. Find the perimeter of the minor sector containing the chord, [Take \(\pi = \frac{22}{7}\)]

A. 14\(\frac{1}{3}\)cm
B. 12\(\frac{5}{6}\)cm
C. 8\(\frac{1}{7}\)cm
D. 7\(\frac{1}{3}\)cm

Your School's Whatsapp Group - Join Us now

WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

Correct Answer: Option A

Explanation

perimeter of minor sector

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

= 2 x 3.5 + \(\frac{120^o}{360^o} \times 2 \frac{22}{7} \times 3.5\)

= 7 + \(\frac{154}{21}\)

= 7 + 7.33

= 14.33

= 14\(\frac{1}{3}\)cm

Previous Next

Go back to Maths classroom

Report an Error Ask A Question Download App