Names of angles formed by lines and a transversal

 

Lines a and b are intersected by line с.

Line с with respect to lines a and b is called a transversal.

Pairs of angles, which are formed when lines a and b are cut by transversal с, have the following special names:

  • Alternate interior angles: 3 and 5, 4 and 6
  • Alternate exterior angles: 2 and 7, 1 and 8
  • Same-side angles (One-sided angles): 4 and 5, 3 and 6
  • Corresponding angles: 1 and 5, 4 and 8, 2 and 6, 3 and 7.

Names of angles formed by lines and a transversal

Angles formed by lines and a transversal

Alternate interior angles are a pair of angles that are in between the parallel lines and on opposite sides of the transversal.

 

Alternate interior angles:

4 and 6,

3 and 5

Alternate interior angles

 

 

Alternate interior angles

Alternative exterior angles are a pair of angles that are outside the parallel lines and on opposite sides of the transversal

Alternate exterior angles:

2 and 7,

1 and 8

Alternative exterior angles

Alternative exterior angles

Same-side interior angles (One-sided angles) lie on the same side of transversal and between the parallel lines.

 

One-sided angles:

3 and 6,

4 and 5

Same-side angles

 

 

Same-side angles

Two angles are corresponding angles when they are on the same side in the same position.

Corresponding angles:

1 and 5,

4 and 8,

2 and 6,

3 and 7.

Corresponding angles

 

 

Corresponding angles

 

 

Corresponding angles

 

 

Corresponding angles