Corresponding Angles
When two lines are crossed by another line (called the Transversal):
The angles in matching corners are called Corresponding Angles.
In this example a and e are corresponding angles
Also:
• b and f are corresponding angles
• c and g are corresponding angles
• d and h are corresponding angles
Parallel Lines
When the two lines being crossed are Parallel Lines the Corresponding Angles are equal.
(Click on "Corresponding Angles" to have them highlighted for you.)