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. The shapes themselves ...

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. The shapes themselves ...

Rectangular or semicircular head protractors have long, thin, unruled blades and heads with direct reading angular graduations. Sine bars, blocks, tables, or plates are used for precision angular ...