Line and Angle Relationships Sec 6.1 GOALS: To learn vocabulary To identify angles and relationships of angles formed by tow parallel lines cut by a transversal

l BA Line Ray Angle AB A B C sides vertex Vocabulary

Types of Angles Acute angles – angles that have measures between 0 and Right angles – angles that have measures equal to Obtuse angles – angles that have measures between Straight angles – angles that have measures equal to

Special Pairs of Angles Vertical angles – opposite angles formed by intersecting lines. Vertical angles are congruent.

Special Pairs of Angles Adjacent angles – angles that have the same vertex, share a common side, and do not overlap. A B C

Special Pairs of Angles Complementary angles – angles whose sum is A B C D

Special Pairs of Angles Supplementary angles – angles whose sum is AB

Examples

Perpendicular Lines Perpendicular lines – lines that intersect at right angles k h

Parallel Lines Parallel lines – two lines in a plane that never intersect or cross k h

7 Transversal A line that intersects two or more other lines is called a transversal. Eight angles are formed when a transversal intersect two lines t

7 Corresponding Angles Postulate Corresponding angles are those in the same position on the two lines in relation to the transversal. If two parallel lines are cut by a transversal, then corresponding angles are congruent

7 Alternate Interior Angles Theorem Alternate interior angles are those on opposite sides of the transversal and inside the other two lines. If two parallel lines are cut by a transversal, then alternate interior angles are congruent

7 Alternate Exterior Angles Theorem Alternate exterior angles are those on opposite sides of the transversal and outside the other two lines. If two parallel lines are cut by a transversal, then alternate exterior angles are congruent

Example Given: Find: x k h

Example Given: Find: x and the angle measure k h

Example Given: Find the angles shown ° k h

Students Given: Find: All other angle measures k h

Homework Page , 19-22, 30-33, 47-49