A wooden model of a square pyramid has a base edge of 12 cm and an altitude of 8 cm. A cut is made parallel to the base of the pyramid that separates it into two pieces: a smaller pyramid and a frustum. Each base edge of the smaller pyramid is 6 cm and its altitude is 4 cm. How many cubic centimeters are in the volume of the frustum

Respuesta :

Answer:

[tex]336\text{ cm}^3[/tex]

Step-by-step explanation:

GIVEN: A wooden model of a square pyramid has a base edge of [tex]12\text{ cm}[/tex] and an altitude of [tex]8\text{ cm}[/tex]. A cut is made parallel to the base of the pyramid that separates it into two pieces: a smaller pyramid and a frustum. Each base edge of the smaller pyramid is [tex]6\text{ cm}[/tex] and its altitude is [tex]4\text{ cm}[/tex].

TO FIND: Volume of frustum.

SOLUTION:

Base edge of bigger square pyramid [tex]=12\text{ cm}[/tex]

Altitude of bigger square pyramid [tex]=8\text{ cm}[/tex]

area of square base [tex]=\text{side}\times\text{side}=12\times12\text{ cm}^2[/tex]

                                  [tex]=144\text{ cm}^2[/tex]

Volume of pyramid [tex]=\frac{1}{3}\times\text{base area}\times\text{height}[/tex]

putting values

                        [tex]=\frac{1}{3}\times144\times8[/tex]

                        [tex]=384\text{ cm}^3[/tex]

Base edge of smaller pyramid [tex]=6\text{ cm}[/tex]

Altitude of smaller pyramid [tex]=4\text{ cm}[/tex]

area of square base [tex]=6\times6=36\text{ cm}^2[/tex]

Volume of small pyramid [tex]=\frac{1}{3}\times36\times4[/tex]

                                          [tex]=48\text{ cm}^3[/tex]

Volume of frustum [tex]=\text{Volume of bigger pyramid}-\text{volume of smaller pyramid}[/tex]

                               [tex]=384-48[/tex]

                               [tex]=336\text{ cm}^3[/tex]

Hence the volume of frustum is [tex]336\text{ cm}^3[/tex]