1. Properties of Parallel Lines & Proving Lines Parallel
3-1 & 3-2
Properties of Parallel Lines & Proving Lines Parallel

2. OBJECTIVES Identify angles formed by two lines and a transversal
To prove and use properties of parallel lines
To relate parallel and perpendicular lines

3. VOCABULARY
Transversal- a line that intersects two coplanar lines at two distinct points
Alternate Interior Angles- nonadjacent interior angles that lie on opposite sides of the transversal
Same Side Interior Angles- lie on the same side of the transversal and in between the two coplanar lines
Two Column Proof- statements and reasons are aligned in two columns
Corrresponding angles- lie on the same side of the transversal and in corresponding positions relative to the two coplanar lines
Alternate Exterior Angles- nonadjacent exterior angles that lie on opposite sides of the transversal
Same Side Exterior Angles- lie on the same side of the transversal and on the outside of the two coplanar lines
Flow Proof- arrows show the logicl connections between the statements. Reasons are written below the statements.

4. Postulates & Theorems

5. Postulates & Theorems

6. Two Column Proof of Theorem 3-1 Flow Proof of Theorem 3-3