Properties of Parallel Lines Learning Target: I can use properties of parallel lines to find angle measures.
A transversal is a line that intersects two coplanar lines at two different points. When a transversal intersects those two lines it creates eight angles
· Inside the two parallel lines ·Opposite sides of the transversal ·Examples 3 & 6 4 & 5 Alternate Interior Angles Alternate Interior Angles are always congruent!
· Inside the parallel lines ·On the same side of the transversal Examples: 3 & 5 4 & 6 Same-Side Interior Angles Same-Side Interior Angles are always supplementary (add to )
Corresponding Angles Li e on the same side of the transversal in corresponding positions Examples: 1 & 5 2 & 6 3 & 7 4 & Corresponding Angles are always congruent.
Alternate exterior angles ·lie on opposite sides of the transversal ·nonadjacent exterior angles
Examples: Find m<1 and m< t n m 1= =105 0
Examples: Find m<1 and m< ab 2 1 q 1=120 2=60
Try this with your partner: Find m<3m<4m<5 m<6m<7m<8 a b c d =130 4=130 5=50 6=50 7=130 8=50
Find m<1 and m<2. 2=70 1=100
(x+40) 0 x0x0 Find the value of the measured angles. x+40+x=180 2x+40=180 2x=140 x=70
Find the value of the labeled angles. (x+40) 0 (3x-10) 0 3x-10=x+40 2x=50 x=25
x0x0 y0y Find x and y. x=70 x+y+50= y+50= y=180 y=60