Sides of the lower base: \({a_1},{a_2}, \ldots ,{a_n}\)

Sides of the top base: \({b_1},{b_2}, \ldots ,{b_n}\)

Scale factor: \(k\)

Height: \(h\)

Slant height: \(m\)

Sides of the top base: \({b_1},{b_2}, \ldots ,{b_n}\)

Scale factor: \(k\)

Height: \(h\)

Slant height: \(m\)

Perimeters of the bases: \({P_1}\), \({P_2}\)

Areas of the bases: \({S_1}\), \({S_2}\)

Total surface area: \(S\)

Lateral surface area: \({S_L}\)

Volume: \(V\)

Areas of the bases: \({S_1}\), \({S_2}\)

Total surface area: \(S\)

Lateral surface area: \({S_L}\)

Volume: \(V\)

- A frustum of a pyramid is a polyhedron that lies between the base of the pyramid and a plane through it parallel to the base.
- The polygons lying in the bases of a frustum of a pyramid are similar to each other:

\({\large\frac{{{b_1}}}{{{a_1}}}\normalsize} = {\large\frac{{{b_2}}}{{{a_2}}}\normalsize} = {\large\frac{{{b_3}}}{{{a_3}}}\normalsize} = \ldots\) \(= {\large\frac{{{b_n}}}{{{a_n}}}\normalsize} = {\large\frac{b}{a}\normalsize} = k,\)

where \(k\) is a scale factor. - Ratio of the base areas

\({\large\frac{{{S_2}}}{{{S_1}}}\normalsize} = {k^2}\) - Lateral surface area of a frustum of a regular pyramid

\({S_L} = m{\large\frac{{{P_1} + {P_2}}}{2}\normalsize},\)

where \(m\) is the slant height, \({P_1}\), \({P_2}\) are the perimeters of the top and bottom bases. - Total surface area

\(S = {S_L} + {S_1} + {S_2}\) - Volume of a frustum of a pyramid

\(V =\) \({\large\frac{h}{3}\normalsize} \left( {{S_1} + \sqrt {{S_1}{S_2}} + {S_2}} \right)\)