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

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प्रश्न

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

उत्तर

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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अध्याय 20: Surface Areas and Volume of A Right Circular Cone - Exercise 20.1 [पृष्ठ ८]

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आरडी शर्मा Mathematics [English] Class 9
अध्याय 20 Surface Areas and Volume of A Right Circular Cone
Exercise 20.1 | Q 14 | पृष्ठ ८

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