Volume of the prism: V=B×H
Base of the prism is a trapezoid, so the volume equation will be:
V=((a+b)/2)×h×H
Information that is given:
h=7 inches(height of the base);
x=5 inches(segment of a side of the trapezoid);
H=4 inches(height of the prism);
b=8 inches(shorter side of the trapezoid).
Calculate the longer side of the trapezoid:
a=2x+b
a=2×5+8=10+8=18 in.
Now you can calculate the base:
B=((a+b)/2)×h
B=((18+8)/2)×7
B=91 in.
Volume of the prism:
V=91 × 4
V=364 inches.