We know that the area of trapezoid is = ( a+b/2 ) × h
Whereas, a is base ( b1 ) and b is another base ( b2 ) and h is height. Given area of trapezoid is = 205 cm²
So the answer of yours question is, Height of trapezoid = 10 cm.
In the pic, As you can see it is the Area of a trapezoid 'A'.