# Definition:Transversal (Geometry)/Corresponding Angles

## Definition

Corresponding angles are the angles in equivalent positions on the two lines cut by a transversal with respect to that transversal.

In the above figure, the corresponding angles with respect to the transversal $EF$ are:

$\angle AHJ$ and $\angle CJF$
$\angle AHE$ and $\angle CJH$
$\angle BHE$ and $\angle DJH$
$\angle BHJ$ and $\angle DJF$

## Also known as

The corresponding angle to an exterior angle is also known as the interior and opposite angle on the same side.

The corresponding angle to an interior angle is also known as the exterior and opposite angle on the same side.

In the words of Euclid:

If a straight line falling on two straight lines make the exterior angle equal to the interior and opposite angle on the same side, or the interior angles on the the same side equal to two right angles, the straight lines will be parallel to one another.