One time around the origin of a coordinate plane is 360 degrees. So in order to get to 453, we will go all the way around once, and then keep going til we get to 453. 453-360 = 93. That means that the coterminal angle is 93. It's terminal side is in Q2. If we are looking to find the reference angle, it is 180-93 which is 87. Usually these are presented in the same chapter in math, if not in the same section.
