2. Protractor
• A simple Protractor is the basic device for
measuring angles. At best, it can provide least
count of one degree for smaller protractor and
half degree for large protractors.
• Like a steel rule, the simple protractor has
limited usage in engineering metrology. But, a
few additions and a simple mechanism, which
can hold a main scale, a Vernier scale and a
rotatable blade, can make it very versatile.