LT 3.1: Identify parallel lines, perpendicular lines, skew lines and angles formed by two lines and a transversal

Math Humor Line l: “Look out! You almost intersected me!!” Line m: “Well skew’s me!!!”

Identify each of the following. 1) One pair of perpendicular segments. 2) One pair of skew 3) One pair of parallel segments. 4) One pair of parallel planes.

Transversal: a line that intersects two coplanar lines at two distinct points. Line t is the transversal of lines a and b. t A b

Corresponding angles: angles that lie on the same side of the transversal and in corresponding positions    

a b Alternate interior angles: nonadjacent interior angles that lie on the opposite sides of the transversal a b t    

a b Alternate exterior angles: nonadjacent exterior angles that lie on the opposite sides of the transversal a b t    

Same-side interior angles: interior angles that lie on the same side of the transversal    

Example 2: Classifying Pairs of Angles Give an example of each angle pair. A. corresponding angles B. alternate interior angles C. alternate exterior angles D. same-side interior angles

Example 3: Identifying Angle Pairs and Transversals Identify the transversal and classify each angle pair. A. 1 and 3 B. 2 and 6 C. 4 and 6 n m

Before you leave… Given: <1 and <2 are supplementary, <1 and <3 are vertical angles Prove: <2 and <3 are supplementary