Part A. 15
Part B. 14.3
To do this you have to use the Pythagorean theorem
a^2+b^2=c^2
In the formula, c always represents the hypotenuse. a and b represents the other two legs.
1. 8^2+b^2=17^2
64+b^2=289
Subtract 64 from both sides
b^2=225
Square root both sides
b=15
2. 14^2+b^2=20^2
196+b^2=400
Subtract 196 from both sides
b^2=204
Square root both sides
b= 14.2828568570857