Same-side interior anglesare interior angles on the same side of a trans-
versal line.
Look for a distinctive C shaped figure.When a transversal intersects a pair of parallel lines, same-side interior
anglesare supplementary.
Alternate interior anglesare interior angles on opposite sides of a
transversal line.
Look for a distinctive Z shaped figure.When a transversal intersects a pair of parallel lines, alternate interior
anglesare congruent.
1
5 4 3 2(^876)
Alternate Interior Angles
∠ 4 ∠ 6
∠ 3 ∠ 5
1
2
3
4
5
(^876)
Same Side Interior Angles
∠ 3 ∠ 6
∠ 4 ∠ 5
501 Geometry Questions