Given:
Lenght =8.2mm , width = 3.5mm and height = 20.1
The volume of pyramid is given by,
V=1/3 (base area) (height)
As it is rectangular pyramid,
first find area of reactangle . this will be base area for pyramid.
area of reactangle=lenght * weight
![\begin{gathered} A=l\cdot w \\ =8.2\cdot3.5 \\ =28.7\text{ cm}^2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/i2fr1ke9u2bi0xde9lrp5twy99vej1hs9q.png)
Volume is,
![\begin{gathered} V=(1)/(3)\cdot A\cdot h \\ =(1)/(3)\cdot28.7\cdot20.1 \\ =192.29\text{ cm}^3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/2k5le8fln9bsa2mu19ncgpd70z2zi44jot.png)