First of all we need to work out the other side of the triangle. To do this, we will use Pythagorean’s Theorem:
a = 7 and b = 25
c² = a² + b²
c² = 7² + 25²
c² = 49 + 625 = 674
c = √674
c = 25.96
Area of a trapezoid = ((a + b) / 2) x h
a = 4
b = 4 + 7 = 11
h = The side of the triangle we just worked out: 25.96
A = ((4 + 11) / 2) x 25.96
A = (15 / 2) x 25.96
A = 7.5 x 25.96
A = 194.7
The area is 194.7units²
