# Measuring Angles

Angles are those which are formed by two rays with common vertex. If one of the ray is fixed and the other is rotated about the fixed vertex, then the angle between the two rays will measure from 0^{o} to 360^{o}. The angles can be classified according to their measure. Measuring angles is the part of practical geometry. We measure the angles to classify into the type of the angles. The angles can be measured to find the angles subtended according to the given condition. **For example,** angle subtended by an object at the retina, angle of elevation of the top of a building, angle of depression of a ship from the top of a hill etc. Measurement of these angles will help us to find the top of a building, distance between the buildings, distance of the ship from the hill or shore etc. In this section let us see how we measure angles.