A cylinder and a cone have equal radii of their bases and equal heights. If their curved surface areas are in the ratio 8:5, show that the radius and height of each has the ratio 3:4.
Given,
Curved surface area of cylinder = curved surface area of cone = 8:5
Let C.S.A of cylinder = 8x
C.S.A of cone = 5x
As mention above cone and cylinder have equal radius and equal height
100h2 = 64h2 + 64r2
100h2 – 64h2 = 64r2
36h2 = 64r2