Answer: 
Step-by-step explanation:
Given
Length L=15 feet
width b=2 feet
Volume V=375 cubic feet
Suppose h is the height
Volume is given by 

45 degrees is the answer to your problem
B. 6.3 Because, for a triangle, you can use the angles to figure out the length. You can also tell that it can’t be D or A because it’s not longer than the base and it’s not small enough to be C.
8*4=32
7*4=28
340÷32=10.625
350÷28=12.5
12.5-10.625= 1.875