What is a conical frustum?

A cone with the top cut off by a plane parallel to the base. Two radii R (bottom), r (top), and height h.

What is the volume formula?

V = (1/3)πh(R² + Rr + r²). R and r are the two base radii.

Lateral surface area = π(R + r)s where s is the slant height: s = √(h² + (R − r)²).

Calculate volume and surface area of a conical frustum (truncated cone) from radii and height.

Bottom radius R

Top radius r

Height h

What is a conical frustum?: A cone with the top cut off by a plane parallel to the base. Two radii R (bottom), r (top), and height h.
What is the volume formula?: V = (1/3)πh(R² + Rr + r²). R and r are the two base radii.
Lateral surface?: Lateral surface area = π(R + r)s where s is the slant height: s = √(h² + (R − r)²).

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