Truncated Cone
A truncated cone is the result of cutting a cone by a plane parallel to the base and removing the part containing the apex.

The height is the line segment that joins the two bases perpendicularly.
The radii are the radii of their bases.
The slant height is the shortest possible distance between the edges of the two bases.

The slant height of the truncated cone is obtained by applying the Pythagorean theorem for the shaded triangle:
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Unfold of a Truncated Cone

Lateral Area of a Truncated Cone
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Surface Area of a Truncated Cone
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Volume of a Truncated Cone
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Examples
Calculate the lateral area, surface area and volume of a truncated cone of radii 2 and 6 cm and a height of 10 cm.

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Calculate the lateral area, surface area and volume of a truncated cone of radii 10 and 12 cm and a slant height of 15 cm.

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