There are 3 types of angles that are congruent: Alternate Interior, Alternate Exterior and Corresponding Angles.

Can you make a Z?

Some people find it helpful to use the 'Z test ' for alternate interior angles.
If you can draw a Z or a 'backwards z', then the alternate interior angles are the ones that are in the corners of the Z

Can you identify each type of congruent angle in the picture below?

Alternate Interior Angles

Answer

$$\angle $$ 3 and $$\angle $$ 6
$$\angle $$ 4 and $$\angle $$ 5

Alternate Exterior Angles

Answer

$$\angle $$ 2 and $$\angle $$ 7
$$\angle $$ 1 and $$\angle $$ 8

Corresponding Angles

Answer

$$\angle $$ 1 and $$\angle $$ 5
$$\angle $$ 4 and $$\angle $$ 8
$$\angle $$ 2 and $$\angle $$ 6
$$\angle $$ 3 and $$\angle $$ 7

Load a Similar Problem?

Line P is parallel to line v

Alternate Interior Angles

Answer

$$ \angle$$D and $$ \angle$$W
$$ \angle$$X and $$ \angle$$C

Alternate exterior angles

Answer

$$ \angle$$A and $$ \angle$$Z
$$ \angle$$Y and $$ \angle$$B

Identify the corresponding angles

Answer

$$ \angle$$A and $$ \angle$$W
$$ \angle$$D and $$ \angle$$Z
$$ \angle$$X and $$ \angle$$B
$$ \angle$$C and $$ \angle$$Y

The Supplementary Angle Pairs

There are 2 types of supplementary angles that are formed: Same side interior and same side exterior

Same Side Interior

Same Side Exterior

Interactive Parallel Line and Angles

Click and Drag Points E and F to explore the relationship of corresponding, alternate interior and alternate exterior angles that are formed
by a transversal and parallel lines. (Full Size Version)

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