Angle Relationships

Vertical angles

angles that are opposite from each other and are formed when 2 lines intersect. Congruent angles.

Adjacent angles

angles that share a vertex and a side, but do not overlap

Complementary angles

are angles that add up to 90 degrees

Straight angles

is an angle that measures 180 degrees and forms a straight line

Obtuse angles

an angle that is greater than 90 degrees but less than 180 degrees

Supplementary angles

angles that add up to 180 degrees

Acute angles

an angle that is less than 90 degrees

Right angle

measures exactly 90 degrees and is known as a "corner" angle

Parallel lines

lines that never intersect

Perpendicular lines

lines that intersect to form a right angle

Congruent angles

angles that have the same measure

Transversal line

a line that intersects two parallel lines

Alternate interior angles

on opposite sides of the transversal and inside the parallel lines

Alternate exterior angles

on opposite sides of the transversal and outside the parallel lines

Same side interior angles

two interior angles on the same side of the transversal

Same side exterior angles

two exterior angles on the same side of the transversal

Corresponding angles

in the same relative position

Remote exterior angles

equal to the sum of its two remote interior angles

Consecutive angles

interior angles that lie on the same side of the transversal

Triangle Angle Sum Theorem

The sum of the measures of the angles of a triangle is 180.