First we find the volume of the triangular prism.
We find the area of the triangle, then we multiply that by the height.
So 7*6/2= 42/2=21
21*10= 210
Then if all the dimensions add another foot on to them then you get: 7, 8, and 11.
Then you do the same thing to find the area of this rectangular prism.
7*8/2=56/2=28
28*11= 308
Now, we calculate the growth from 210 to 308 in this proportion: 308/210=x/100
Solving it we get (cross multiplying):
210x=30800
x=146 2/3 or 146.66 percent increase.
I hope this helps!
