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Solution for The Diameters of Two Cones Are Equal. If Their Slant Heights Are in the Ratio 5 : 4, Find the Ratio Of Their Curved Surfaces. - CBSE Class 9 - Mathematics

ConceptSurface Area of a Right Circular Cone

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

Is there an error in this question or solution?

APPEARS IN

R.D. Sharma Mathematics for Class 9 by R D Sharma (2018-19 Session) (with solutions)
Chapter 18: Surface Areas and Volume of a Cuboid and Cube
Q: 14
Solution for 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. concept: Surface Area of a Right Circular Cone. For the course CBSE
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