Trapezoidal Land Perimeter Calculation

A piece of land is shaped like a trapezoid, where the lengths of the two parallel sides are 15 meters and 25 meters, and the distance between them (the height) is 10 meters. Additionally, a fence surrounds the area, and the total length of the fence is equal to the sum of the lengths of the two parallel sides as well as the lengths of the two non-parallel sides that are equal in length. If we denote the length of the non-parallel sides as $x$ meters, what is the expression for the perimeter of the land as a function of $x$?

The perimeter $P$ can be calculated using the formula:

$P = (a + b) + 2x$ where:

$a$ = length of the first parallel side,

$b$ = length of the second parallel side.