A cone of radius 4 cm with a slant height of 12 cm was sliced horizontally, resulting into a smaller cone (upp

Question

A cone of radius 4 cm with a slant height of 12 cm was sliced horizontally, resulting into a smaller cone (upper portion) and a frustum (lower portion). If the ratio of the curved surface area of the upper smaller cone and the lower frustum is 1:2, what will be the slant height of the frustum?

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Accepted Answer

12 − 4 3 12-4\sqrt{3} 12 − 4 3 ​. The ratio of the curved surface area of the upper cone to the lower frustum is 1:2. => the ratio of the curved surface area of the upper cone to the total cone = 1:3. Curved surface area (CSA) of a cone = π ∗ r ∗ l \pi*r*l π ∗ r ∗ l For the given cone, the slant height, l = 12 l=12 l = 12 cm CSA