Solve the Perimeter Equation: Finding X in a Trapezoid

To solve this problem, we'll utilize the formula for the perimeter of a trapezoid.

The formula for the perimeter is given by:

• $P = a + b + c + d$

From the problem, we know:

• The perimeter $P$ is 36.
• The side lengths are 13, 12, and 5, with the unknown side as $x$.

Plug these into the formula:

$36 = 13 + 12 + 5 + x$

Combine the known side lengths:

$36 = 30 + x$

To isolate $x$, subtract 30 from both sides:

$x = 36 - 30$

Calculate the result:

$x = 6$

Therefore, the length of the missing side $x$ is 6.

Thus, the correct answer is choice 2, corresponding to $x = 6$.