WAEC - Mathematics (1990 - No. 12)

An arc of length 22cm subtends an angle of θ at the center of the circle. What is the value of θ if the radius of the circle is 15cm?[Take π = 22/7]

70^o

84^o

96^o

156^o

168^o

\(2\pi r = 2 \times 3.142 \times 15 = 94.28cm\)

\(94.28cm = 360°\)

\(1cm = \frac{360°}{94.28}\)

\(\therefore 22cm = \frac{360°}{94.28} \times 22\)

= 84°