27pi/10 *180/pi= 486, but since we want a coterminal angle between 0 and 2pi we substract 360, 486-360= 126 (this is the answer in degree form), =126* pi/180= 7pi/10
to make sure this is the right answer we have to check if the reference angles are the same, which is this case they are. (180-126= 54) (540-486=54)