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