The area of a trapezoid is:

A = h * (base 1 + base 2) / 2

We're given the area in the problem, so we can plug that into this equation.

2.52 = h * (base 1 + base 2) / 2

Multiply both sides by 2.

5.04 = h * (base 1 + base 2)

Unfortunately, the problem doesn't give the value of both bases of the trapezoid, so we will have to leave those alone. We can, however, divide both sides by it

5.04 / (base 1 + base 2) = h

So whatever the length of base 1 and base 2 is, plug that into this equation to get an actual value for height.