Answer:
The height of the cross section is [tex]4\ ft[/tex]
Step-by-step explanation:
we know that
The area of trapezoid is equal to
[tex]A=\frac{1}{2}(b1+b2)h[/tex]
In this problem we have
[tex]A=76\ ft^{2}[/tex]
[tex]b1=34\ ft[/tex]
[tex]b2=4\ ft[/tex]
substitute and solve for h
[tex]76=\frac{1}{2}(34+4)h[/tex]
[tex]152=(38)h[/tex]
[tex]h=152/38=4\ ft[/tex]
