Question

A rectangular prism is made of 81 unit cubes. The prism is 9 unit cubes long.

Answer 1

Answer:

A width: 3 unit cubes

height 3 unit cubes

Step-by-step explanation:

Volume of rectangular prism = 81 unit cubes

$l$ = Length of rectangular prism = 9 unit cubes

$w$ = Width of rectangular prism

$h$ = Height of rectangular prism

Volume of a rectangular prism is given by

$V=lwh\\\Rightarrow 81=9wh\\\Rightarrow wh=\dfrac{81}{9}\\\Rightarrow wh=9$

The product of width and height must be 9 so from the options this is only possible when width and height both are 3 units.

So, the width is 3 unit cubes and the height is 3 unit cubes.