Answer:
2940
Explanation:
Surface Area of a rectangular prism is 2(LW)+2(HW)+2(LH)
We have that the surface area is 1414 where L=c , H=20, W=7
Let's plug all of this in to solve for c:
2(LW)+2(HW)+2(LH)=1414
2(c*7)+2(20*7)+2(c*20)=1414
14c+280+40c=1414
54c+280=1414
54c=1414-280
54c=1134
c=1134/54
c=21
Now the volume of a rectangular prism is V=L*W*H
So plug in our values L=21, H=20, W=7
V=21*20*7=2940