The diagram above shows a cone with the dimensions of its frustrum indicated. Calculate the height of the cone.
-
A.
12cm -
B.
15cm -
C.
18cm -
D.
24cm -
E.
30cm
Correct Answer: Option D
Explanation
Considering the smaller and larger triangle, these two are similar triangles. Hence,
If the height of the smaller triangle = h,
(therefore frac{h}{6} = frac{h + 12}{12})
(12h = 6h + 72 implies 6h = 72)
(h = 12 cm)
(therefore) The height of the cone = 12 + 12 = 24 cm