A pyramid has a square base. The side of square is 12 cm and height of pyramid is 21 cm. The pyramid is cut into 3 parts by 2 cuts parallel…

NA

Volume of pyramid = $ \frac{1}{3} \times $ area of base $\times$ height


$ = \frac{1}{3} \times 12 \times 12 \times 21 $


$ = 1008 $


side of square of upper base


$\frac{a_1}{a_3} = \frac{7}{21} $


$a_1 = 4$


$\frac{a_2}{a_3} = \frac{14}{21} $


$a_2 = 8$


Volume of upper and middle portion $=\frac{1}{3} \times 8 \times 8 \times 14 = \frac{896}{3} $


Volume of only bottom = $ 1008 - \frac{896}{3} = \frac{2128}{3} $


Bottom - Top = $ \frac{2128}{3} - \frac{112}{3} = \frac{2016}{3} = 672 $