The trapezoids are similar which means the bigger one is a multiple of the smaller one.
compare the like sides to see the multiple is 4
20 = 5x
4 = x
the sides of ABCD are 4 times bigger than EFGH
**Area is not directly related
The area of a trapezoid = h(a+b)/2
where a and b are the top/bottom sides
A = 4h * 4(a+b)/2
A = 16 * h(a+b)/2
Then the area of ABCD is:
= 16 * 40 cm²
= 640 cm²