Key Terms Understanding Geometry

One angle that measures exactly 180 degrees

• Right angle

• Straight angle

• Supplementary angles

• Complementary angles

Angles that have a common side and the same vertex.

• Adjacent angles

• Vertical angles

• Straight angles

• Complementary angles

Two angles that add to 90^o .

• Supplementary angles

• Perpendicular angles

• Complementary angles

• Congruent angles

Two angles that add up to 180^o .

• Complementary angles

• Supplementary angles

• Straight angle

• Right angle

Two lines that intersect at right angles.

• Parallel lines

• Perpendicular lines

• Congruent lines

• Transversal.

Two lines that NEVER intersect.

• Parallel lines

• Perpendicular lines

• Congruent lines

• Transversal.

Angles across from each other when 2 lines intersect (all congruent)

• Right angles

• Supplementary angles

• Adjacent angles

• Vertical angles

A line that intersects parallel lines.

• Transversal

• Congruent

• Perpendicular

• Parallel

Identify the figure

• Angle

• perpendicular lines

• plane

• line segment

Identify the figure

• intersecting-lines

• plane

• parallel lines

• line