
Answer:
Step-by-step explanation:
Let x be the height ..... then the base = 2x + 2
So we have
Area = (1/2) (base) (height)
20 = (1/2)(2x + 2)(x) simplify
20 = x (x + 1)
20 = x^2 + x subtract 20 from both sides
x^2 + x - 20 = 0 factor
(x + 5) ( x - 4) = 0
Only the second factor makes sense
x - 4 = 0 add 4 to both sides
x = 4 ft and this is the height
And the base = 2(4) + 2 = 10 ft