The first two could be coterminal angles. That means that when drawn, the they appear to be the same angle. For example, 360 degrees and 0 degrees are coterminal.
To determine if an angle is coterminal, add or subtract 2pi from it. In degrees, 2pi is equal to 360, so we are just removing full revolutions to see if the angle ends in the same position.
19pi/4 - 2pi = 7pi/4
7pi/4 - 2pi = -5pi/4