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.

If two 90 degree angles are placed back-to-back (Figure 5), they total 180 degrees. The sides of this angle form a straight line, so a 180 degree angle is a straight line. Adding two more 90 degree ...

A protractor acts in a similar way to a ruler in that it allows you to both measure and draw accurately. The two most popular types are the semi-circular (0-180 degrees - pictured above ) and a ...