After the turn, if you are in the original direction: the degree of two turns remains the same, and the direction changes.

For example, a car turns 45 degrees to the left for the first time and then turns () degrees to the original direction for the second time?

Solution: Turn right 45 degrees.

After turning, if you are in the opposite direction: the degrees of the two turns are complementary and the direction remains the same.

For example, a car turns 45 degrees to the left for the first time, turns () degrees for the second time and then turns back in the opposite direction?

Solution: Turn left 135 degrees.