Download Math Lab – 6.1 Line and Angle Relationships Acute angles – angles

Math Lab – 6.1 Line and Angle Relationships
Acute angles – angles with measures less than 90 degrees
Right angles – angles with measures equal to 90 degrees
Obtuse angles – angles with measures between 90 and 180 degrees
Straight angles – angles with measures equal to 180 degrees
Reflex angles – angles with measures between 180 and 360 degrees
Vertical angles - are opposite angles formed by intersecting lines. Vertical angles are
congruent.
Adjacent angles - have the same vertex, share a common side and do not overlap.
Complementary angles – the sum of the measures of two angles equal to 90 degrees
Supplementary angles – the sum of the measures of two angles equal to 180 degrees
Perpendicular lines – are lines that intersect at right angles
Parallel lines - are two lines in a plane that never intersect
Missing Angle Measures
You can use the relationship between pairs of angles to find missing measures.
Transversal – a line that intersects two or more other lines. When a transversal intersects two
lines, eight angles are formed that have special names.
Alternate interior angles – those on opposite sides of the transversal and inside the other two
lines. They are congruent.
Alternate exterior angles – those on opposite sides of the transversal and outside the other
two lines. They are congruent.
Corresponding angles – those in the same position on the two lines in relation to the
transversal. They are congruent.