Trapezoid Area Formula. According to the trapezoid area formula, the area of a trapezoid is equal to half the product of the height and the sum of the two bases. Area = ½ x (Sum of parallel sides) x (perpendicular distance between the parallel sides).
b1: base 1
b2: base 2
b1 = 15m
b2 = 11m
a = 65m2
The height would be 5m