JAMB - Mathematics (2024 - No. 4)
Find the angle subtended by an arc 33cm long of a circle of diameter 28cm.
105\(^0\)
115\(^0\)
120\(^0\)
135\(^0\)
คำอธิบาย
Length of Arc = \(\frac{\theta}{360}\) x 2\(\pi\)r
Length of arc = 33cm, diameter = 28cm → r = 14cm
33 = \(\frac{\theta}{360} \times 2 \times \frac{22}{7}\times14\)
\(\theta\) = \(\frac{33 \times 180}{22 \times 2}\)
\(\theta\) = 135º