Find the measure of angle age

1. what is the phythaforean theorem? 2.what do we use it for? 1.what is the distance formula ? 2.what do we use it for?

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

For f(x) = 3x+1 and g(x) = x2 - 6, find (g/f)(x)