A cone is formed by bending a sector of a circle having an angle of 210o. Find the radius of the base of the cone if the diameter of the circle is 12cm.
-
A.
12cm -
B.
7.00cm -
C.
1.75cm -
D.
21cm -
E.
3.50cm
Correct Answer: Option E
Explanation
If diameter of the circle = 12cm; radius of the circle(L) = (frac{12}{2})
= 6cm
(frac{theta}{360}) = (frac{r}{L}) where (theta) = 210(theta), L = 6cm
(frac{210}{360}) = (frac{r}{6})
where r = radius of the base of the cone
V = (frac{1260}{360})
= 3.50cm