The diameter of two cones are equal. If their slant heights be in the ratio of 5 : 4. Find the ratio of their curved surface areas ?
Let their slant height be 5x and 4x.
Given that diameter of two cones are equal
∴ R1 = R2 = R
S1 = πRl = πR(5x)
S2 = πRl = πR(4x)
S1/S2 = πR(5x)/ πR(4x) = 5/4
S1/S2 = 5/4
S1 : S2 = 5 : 4