Coterminal angles are those that have a common terminal side. To find a coterminal angle for any given angle we need to add or subtract 360º or 2pi radians.
a) We were given the angle 775º and we need to find the coterminal angle in the range of 0º to 360º. Since the number is greater than the range we have to subtract 360º.
The angle is still outside of the range, therefore we will subtract again.
The coterminal angle to 775º that is in the range from 0 to 360º is 55º.
b) Since the angle is already in the desired range and every angle is coterminal with iself, then the angle we are looking for is 2pi/10.