The area of a rectangle is length x width. We can find the 3 areas of the rectangles with this formula:
20 x 5 = 100
100 yd²
15 x (20-14) = 90
90 yd²
14 x 10 = 140
140 yd²
The area of a trapezoid is 1/2(b1+b2)h
In this problem:
b1=25-15-5
b1=5
b2=10
h=20-14
h=6
We can then plug this into the formula:
A = 1/2(5+10)(6)
A = 1/2(15)(6)
A = 45 yd²
We can then get the area of the whole polygon by adding up the areas of the three rectangles and trapezoid:
A = 100+90+140 + 45
A = 375 yd²