Can someone help me with this? I'm stuck. Thanks! :)

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

What is the question ehre