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प्रश्न
The slant height of the frustum of a cone is 5 cm. If the difference between the radii of its two circular ends is 4 cm, write the height of the frustum.
उत्तर
Slant height of the Frustum = 5 cm
`i.e . l = 5 cm.`
`r_1 - r_2 = 4cm.`
`l = sqrt(h^2 + (r_1 - r_2)^2)`
`5 = sqrt(h^2 + (4)^2)`
Squaring both sides we get
`25 = h^2 + 4^2`
`25 = h^2 + 16`
`25 - 16 = 4^2`
`or h^2 = 9 cm`
`4 = 3 cm`
Height of the Frustum = 3 cm
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