Answer: 7.2
Step-by-step explanation:
Since this is a right triangle we can use the Pythagorean theorem to solve for side b.
Pythagorean theorem: a²+b²=c²
Since the side length opposite the right angle is the hypotenuse we plug 11.2 in for C
(8.6)² + b²=(11.2)²
73.96 + b² = 125.44
b²=51.48
b = 7.17495644586
b=7.2