To answer this question you must use Pythagorean theorem
a and b are the legs (the sides that form a perpendicular/right angle)
c is the hypotenuse (the side opposite the right angle)
In this case...
a = 8
b = unknown
c = √113
^^^Plug these numbers into the theorem
Simplify
64 + b² = 113
solve for x
= 49
Take the square root of both sides to cancel out the square from the b:
√b² = √49
b = 7
Hope this helped!
~Just a girl in love with Shawn Mendes