Question

The diameters of two cones are equal. If their slant heights are in the ratio 5 : 4, find the ratio of their curved surfaces. 

Answer 1

Given that,
Diameters of two cones are equal 

∴ Their radius are also equal i.e., `r_1=r_2` 

Let the ratio of slant height be x 

∴` l_1=5x and l_2=4x`

∴ Ratio of curved surface area =`C_1/C_2` 

∴ `C_1/C_2=(pir_1l_1)/(pir_2l_2)=(pir_1sx)/(pir_2(4x)=)5/4` 

∴ Ratio of curved surface area = 5:4