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]
70o
84o
96o
156o
168o
توضیح
\(2\pi r = 2 \times 3.142 \times 15 = 94.28cm\)
\(94.28cm = 360°\)
\(1cm = \frac{360°}{94.28}\)
\(\therefore 22cm = \frac{360°}{94.28} \times 22\)
= 84°