Using a protractor. Knowing the range of each type of angle, ... So, you need to be very careful which scale you use when measuring the angles. With a protractor, ...

The angles could have any number of degrees. Some rooms, buildings, or windows may be trapezoids. To copy a trapezoid, use a ruler to measure the sides. Copy the angles with the method described above ...

So, you need to be very careful which scale you use when measuring the angles. With a protractor, the angles of any shape can found where two lines meet and form a corner.