F3 Maths Chapter 4:Mensuration
Notice that steps are required to the following question and figures will not given.
14. A circular cone is divided into three portions A, B and C by planes parallel to the base as shown in the figure. The slant heights of the three portions are equal in length. Find the ratio of the volumes of portions A, B and C.
- ☂雨後晴空☀Lv 710 年前最愛解答
Let the height of the cone be 3h :
A : (A+B) : (A+B+C) = h^3 : (2h)^3 : (3h)^3 = 1 : 8 : 27
A : B : C
= A : (A+B - A) : (A+B+C - (A+B) )
= 1 : (8 - 1) : (27 - 8)
= 1 : 7 : 19