They Started Off With 42/7 Instead Of 4/7
B = 2 + 2H
A = 20 ft^2
H = H
Since the Area of a Triangle is Base * Height then the formula should be:
A = BH
20 = H(2+2H)
20 = 2H^2 + 2H
0 = 2H^2 + 2H - 20
Find the zeros of the quadratic equation through substituting the values of a,b, and c. You will get the zeros of x = 2.7 and -3.7. The only thing that would make sense is you use the x=2.7 because there are no negative heights.
Since b = 2h+2
b= 2(2.7) + 2
b= 5.4 + 2
b=7.4
I don't know where you got 4 and 10, but what I got is different.
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