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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.
Solution
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
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