WAEC - Mathematics (2007 - No. 33)
A sector of a circle of radius 14cm containing an angle 60o is folded to form a cone. Calculate the radius of the base of the cone
5\(\frac{1}{2}cm\)
4\(\frac{2}{3}cm\)
3\(\frac{1}{2}cm\)
2\(\frac{1}{3}cm\)
설명
Length of arc = circumference of the base of the
cone \(\frac{\theta}{360} \times 2\pi R = 2 \pi r\)
\(\frac{\theta R}{360}\) = r
r = \(\frac{60 \times 14}{360}\)
= \(\frac{7}{3} = 2\frac{1}{3}\)cm
cone \(\frac{\theta}{360} \times 2\pi R = 2 \pi r\)
\(\frac{\theta R}{360}\) = r
r = \(\frac{60 \times 14}{360}\)
= \(\frac{7}{3} = 2\frac{1}{3}\)cm