THE WAY YOU CHACK THE ANSWER IS BY SUBTRACTING 31-17 AND SEEING IF IT GIVES YOU 14 OR THE OTHER WAY AROUND
The length is 11.27
This can be found using the Pythagorean theory.<span />
ANSWER
The radius is 4
EXPLANATION
The given equation is:

We complete the square to get the expression in standard form:


We factor using perfect squares to get:

This implies that,

Comparing to

The radius is r=4
1. is 5 dollars an hour
2.it represents the amount of money he gets in an hour
Sorry i could not help with 3 and 4
WE HAVE STEM BRAINS