9.1.1 Vocabulary

Two angles that add to equal 90 degrees

• Supplementary Angles

• Adjacent Angles

• Complementary Angles

• Right Angle

Two angles that add to equal 180 degrees

• Complementary Angles

• Supplementary Angles

• A line

• Vertical Angles

Two angles that share a common vertex, common side, and share no common inside points

• Vertical Angles

• Adjacent Angles

• Acute Angles

• Linear Pairs

Two opposite angles formed by intersecting lines

• Adjacent Angles

• Vertical Angles

• Obtuse Angles

• Supplementary Angles

Two angles that form a line and are adjacent and supplementary

• Complementary Angles

• Adjacent Angles

• Supplementary Angles

• Linear Pair

Angles that are inside parallel lines and on opposite sides of the transversal

• Consecutive (Same-Side) Interior Angles

• Alternate Exterior Angles

• Alternate Interior Angles

• Corresponding Angles.

Angles that are outside parallel lines and on opposite sides of the transversal

• Alternate Exterior Angles

• Alternate Interior Angles

• Corresponding Angles

• Vertical Angles

Angles that are inside parallel lines and on the same side of the transversal

• Consecutive Interior Angles or Same Side Interior Angles

• Consecutive Exterior Angles or Same Side Exterior Angles

• Corresponding Angles

• Supplementary Angles

Angles that are in the same position

• Corresponding Angles

• Adjacent Angles

• Alternate Interior Angles

• Linear Pair

Alternate Interior Angles are ____________

• Congruent

• Supplementary

• Neiher