Geometry Postulates and Theorems

two lines are perpendicular, they form four right angles.

• Perpendicular Lines Theorem

• Parallel Lines Postulate

• Angle Addition Postulate

• Transversal Theorem

in the same position on two parallel lines cut by a transversal.

• Corresponding Angles

• Alternate Interior Angles

• Consecutive Interior Angles

• Vertical Angles

two parallel lines are cut by a transversal, then alternate exterior angles are congruent.

• Alternate Exterior Angles Theorem

• Corresponding Angles Postulate

• Consecutive Interior Angles Theorem

• Vertical Angles Theorem

two parallel lines are cut by a transversal, then corresponding angles are congruent.

• Corresponding Angles Postulate

• Alternate Interior Angles Theorem

• Same-Side Interior Angles Theorem

• Vertical Angles Theorem

that intersect to form right angles.

• Parallel Lines

• Perpendicular Lines

• Oblique Lines

• Intersecting Lines

a transversal is perpendicular to one of two parallel lines, it is perpendicular to the other.

• Perpendicular Transversal Theorem

• Alternate Interior Angles Theorem

• Corresponding Angles Postulate

• Converse of the Same-Side Interior Angles Theorem

two parallel lines are cut by a transversal, then consecutive interior angles are supplementary.

• Consecutive Interior Angles Theorem

• Alternate Interior Angles Theorem

• Corresponding Angles Postulate

• Vertical Angles Theorem

Which type of lines have the same slope?

• Perpendicular Lines

• Intersecting Lines

• Parallel Lines

• Skew Lines

on the same side of the transversal and outside the two lines.

• Consecutive Exterior Angles

• Alternate Interior Angles

• Corresponding Angles

• Consecutive Interior Angles

ray that divides an angle into two congruent angles.

• Angle Bisector

• Angle Divider

• Angle Splitter

• Angle Separator