Answer:
C: 12.5
Step-by-step explanation:
The sides x and 11 could be defined as the Adjacent angle and the Hypotenuse. This means that we will use the cos function to solve this.
First we can set up our equation
Next we can solve for x by multiplying by x and dividing by 
the surface area of that rectangular prism is 247.5.
Number 3 it is a factor because if u expand you will see that x+6 will be the answer
Set up a system of equations:
B=2+3C
B+C=90
The variable B is already solved, so plug into bottom equation:
2+3C+C=90
2+4C=90
4C=88
C=22
Plug C back in:
B+22=90
B=68
So B is 68 degrees and C is 22 degrees
Hope this helped!
First you divide 17.5/ 3 and then the answer multiply by 15 and get 87.5 i think
