Answer:
Substitution rule is one of the most important rule to solve the integrals problem.
In substitution rule we substitute different variable in such a way that it can simplify the question.
example: when we have to solve "Sin x²" we cannot solve it but
if question is "x Sin x²" we can substitute x² with t and can solve it.
The purpose of substitution rule is to simplify the problem of integrals.
<em>V = 120 in^3</em>
<u><em>Here is why:</em></u>
The volume formula for a pyramid is:

The B stands for the area of the base, which in this case is a right triangle. We will find the area of the right triangle first, then plug it into the equation.
The area formula for a triangle is:

Plug in the numbers.

A = 45
Now we have found the area of B, we can plug it into the volume formula for the pyramid.

V = 120 in^3