We know that the sum of all angle measures in a trapezoid is 360* (* means degrees)
Therefore we can construct the equation
(X+28)+(x)+(4x-14)+(4x-14)= 360
Now add like terms
10x = 360
And divide by the coefficient of X (aka 10)
X= 36
2.0612439*10^7 should be your answer
Using the SA formula you'll have to substitute in the edge length for s.
SA = 6(312)²
SA = 584064
The surface area is 584,064 feet²
Hope this helps :)
