1. Section 3-1 Lines & Angles

2. Key Concepts Parallel and Skew Parallel Lines – Coplanar lines that do not intersect. Skew Lines – Non coplanar lines. They are not parallel and do not intersect. Parallel Planes – Planes that do not intersect. Symbols are Skew plane ABCD // plane EFGH // means is parallel to

3. Ex 1. Identifying nonintersecting lines and planes.  Which segments are parallel to ?  Which segments are skew to ?  What are two pairs of parallel planes?  Which segments are parallel to plane BCGF? ABCD // EFGHDCG // ABE

4. Transversal Exterior Interior A transversal is a line that intersects two or more coplanar lines at distinct points, creating interior and exterior angles. 1 2 3 4 5 6 7 8

5. Key Concepts Angle Pairs Formed by Transversals Alternate Interior Angles – are nonadjacent interior angles that lie on opposite sides of the transversal. Same-side Interior Angles – are interior angles that lie on the same side of the transversal. 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

6. Key Concepts Angle Pairs Formed by Transversals Corresponding Angles – lie on the same side of the transversal and are in the same position. Alternate Exterior Angles – are nonadjacent exterior angles that lie on opposite sides of the transversal. 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

7. HW: p. 143 #’s 1-3, 17-23 when question asks for all, just put one, 25-42, 49-60 skip 52