A contractor protractor, also known as a construction protractor or an adjustable protractor, is used similarly to a wood protractor but offers more flexibility in measuring angles. To use a contractor protractor, place it on your work surface and adjust it to match one of the lines on your angle by sliding its movable arm back and forth. Ensure that both arms are touching each line of your angle while keeping them locked in position using any locking mechanism present. Finally, read and record the measurement indicated on either side to determine the angle's value in degrees.