Parallel Lines & Transversals

Lessons 3.3 Angles formed by Transversals You will learn to… * identify angles formed by transversals

transversal – a line that intersects two or more coplanar lines at different points no transversal

Occupy corresponding positions corresponding angles 1 2 3 4 6 5 7 8 2 5 1 6 4 8 3 7 Occupy corresponding positions

alternate interior angles Lie between two lines on opposite sides

alternate exterior angles 2 7 2 7 1 8 1 8 4 3 6 5 Lie outside two lines on opposite sides of transversal

same-side interior angles 1 2 3 4 6 5 4 3 6 5 7 8 Lie between two lines on same side of transversal

A line, ray, or segment that intersects 2 or more COPLANAR lines, rays, or segments. transversal transversal Parallel lines Non-Parallel lines Transversal

INTERIOR –The space INSIDE the 2 lines EXTERIOR -The space OUTSIDE the 2 lines exterior

Special Angle Relationships Interior Angles <3 & <6 are Alternate Interior angles <4 & <5 are Alternate Interior angles <3 & <5 are Same Side Interior angles <4 & <6 are Same Side Interior angles 1 4 2 6 5 7 8 3 Exterior Angles <1 & <8 are Alternate Exterior angles <2 & <7 are Alternate Exterior angles <1 & <7 are Same Side Exterior angles <2 & <8 are Same Side Exterior angles Special Angle Relationships

Special Angle Relationships WHEN THE LINES ARE PARALLEL ♥Alternate Interior Angles are CONGRUENT ♥Alternate Exterior Angles are CONGRUENT ♥Same Side Interior Angles are SUPPLEMENTARY ♥Same Side Exterior Angles are SUPPLEMENTARY 1 4 2 6 5 7 8 3 If the lines are not parallel, these angle relationships DO NOT EXIST.

Let’s Practice m<1=120° Find all the remaining angle measures. 1 4 6 5 7 8 3 m<1=120° Find all the remaining angle measures. 120° 60° 120° 60° 120° 60° 120° 60° Let’s Practice

Another practice problem 40° Find all the missing angle measures, and name the postulate or theorem that gives us permission to make our statements. 120° Another practice problem

Assignment Pg 160, 13-33 3.3 A & B