FIRST PROBLEM AS GENIUS!!!
The 45-45-90 triangle theorem states that each leg equals x, and the hypotenuse equals

. Using this, we can find that the height is 10. Take the average of the lengths to get l = 27.
The area = 270.
The answer is 6t^2+2.5x^2-0.5t-5.4
Answer:
number, variable, or a product of a number and one or more variables
Let Surface Area A, a the base edge and h the height:
A = a²+2a√(a²/4+h²)
h=?
pythagorean theorem:
h²=c²-a²
h=√(c²-a²)
h=√(8²-(.7/2)²)= 8
plug it in the above equation A= 11.7ft²
So A is correct