JAMB - Mathematics (2020 - No. 32)
A sector of circle of radius 7.2cm which substends an angle of 300\(^o\) at the centre is used to form a cone. What s the radius of the base of the cone?
8cm
9cm
6cm
7cm
설명
r = radius of the cone's base, R = radius of the circle
r = \(\frac{R \theta}{360}\) = \(\frac{7.2 \times 300}{360}\) = 6cm