The information provided says that angle 1 is supplemental to angle 2 which means that both angles added together equal 180 degrees. Since angle 1 equals 68 degrees it means that 180 degrees minus 68 degrees of angle one gives us the answer of angle 2 equals 112 degrees. Angle 1 is complimentary with angle 3 which means they equal 90 degrees together and with angle 1 being equal to 68 degrees then angle 3 equals 22 degrees. Lastly angle 2 minus angle 3 = 112 - 22 = 90 degrees
