The vernier bevel protractor is a precision instrument meant for measuring angles to an accuracy of 5 minutes.

The Least count of vernier bevel protractor is 5' (Five Minutes)

The value of each Vernier scale division of Vernier bevel protractor is 1 degree 55 minutes.

To get the least count of 5 minutes (5') in a vernier bevel protractor the 23 degree main scale is divided into 12 equal parts on vernier scale.

**Following are the parts of a vernier bevel protractor.**

**Stock** : – This is one of the contacting surfaces during the measurement of an angle. Preferably it should be kept in contact with the datum surface from which the angle is measured.

**Dial**:– The dial is an integrated part of the stock. It is circular in shape, and the edge is graduated in degrees.

**Blade**:- This is the other surface of the instrument that contacts the work during measurement. It is fixed to the dial with the help of the clamping lever. A parallel groove is provided in the centre of the blade to enable it to be longitudinally positioned whenever necessary.

**Locking Screws**:- Two knurled locking screws are provided, one to lock the dial to the disc, and the other to lock the blade to the dial.

**Acute Angle**: An angle which measures less than 90 Degree is called an acute angle.

**Right Angle**: An angle which measures exactly 90 Degree is called a right angle.

**Obtuse Angle**: An angle that measures greater than 90 degree and up to 180 Degree is known as the obtuse angle

**Straight Angle**:The angle which measures exactly 180 Degree is called a straight angle.

**Reflex Angle**: The angle which measures greater than 180 Degree and less than 360 Degree is known as the reflex angle.

**Full Angle**: The angle which measures exactly 360 Degree is called a straight angle.