ALTERNATE INTERIOR ANGLES A pair of angles in which one arm of each of the angles is on opposite sides of the transversal and whole other arm include segment PQ as shown in Fig.44 is called a pair of alternate interior angles.

Alternate interior angles a pair of angles in which one arm of each of the angle is on opposite sides of the transversal and whose other arms include segment PQ as shown in Fig.15.15 is called a pair of alternate interior angles.

ALTERNATE EXTERIOR ANGLES A pair of angles in which one arm of each of the angles is on opposite sides of the transversal and whose other arms are directed in opposite direction and do not include segment PQ is called a pair of alternate exterior angles.

Alternate exterior angles a pair of angles in which one arm of each of the angles is on opposite side of the transversal and whose other arms are directed in opposite direction and do not include segment PQ is called a alternate exterior angles.

CORRESPONDING ANGLES A pair of angles in which one arm of both the angles is no the same sides of the transversal and their other arms are directed in the same sense is called a pair of corresponding angles.

Corresponding angles a pair of angles in which one arm of both the angles is on the same side of the transversal and their other arms are directed in the same sense is called a pair of corresponding angles.

Interior angles the angles whose arms include line segment PQ are called interior angles.

Transversal; Corresponding Angles and Alternate Interior Angles

If two lines are intersected by a transversal; the bisectors of any pair of alternate interior angles are parallel.

If two parallel lines are intersected by a transversal then prove that the bisectors of any pair of alternate interior angles are parallel.

The ratio of two interior angles on the same side of the transversal is 2:3 , the measure of difference of both the angles is -