Geometry 3.1-3.4

Front 1

parallel lines

Back 1

coplanar lines that never intersect
(symbol is ll)

Front 2

skew lines

Back 2

noncoplanar lines that never intersect

Front 3

parallel planes

Back 3

planes that never intersect

Front 4

alternate interior angles

Back 4

two angles inside the two lines but on opposite sides of the transversal
(AIA - makes a Z or N)

Front 5

alternate exterior angles

Back 5

two angles on opposite sides of the transversal and outside of the two lines
(AEA)

Front 6

consecutive interior angles

Back 6

two angles on the same sid of the trasversal and inside both lines
(CIA - make goal posts - aka same side interior angles)

Front 7

corresponding angles

Back 7

two angles in the same position relative to the two lines and the transversal

Front 8

parallel postulate

Back 8

If there is a line and a point not on a line, then there is exactly one parallel through that point to the given line.

Front 9

perpendicular postulate

Back 9

If there is a line and a point not on the line, then there is exactly one perpendicular through that point to the given line.

Front 10

corresponding angles postulate

Back 10

if 2 parallel lines are cut by a transversal then corresponding angles are congruent
(corr. ang. post.)

Front 11

alternate interior angles theorem

Back 11

if 2 parallel lines are cut by a transversal than alternate interior angles are congruent
(AIA theorem)

Front 12

consecutive interior angles theorem

Back 12

if parallel lines are cut by a transversal the consecutive interior angles are supplementary
(CIA theorem)

Front 13

alternate exterior angles theorem

Back 13

if parallel lines are cut by a transversal the alternate exterior angles are congruent
(AEA theorem)

Front 14

6 methods to prove lines are parallel

Back 14

1. show corr. < are congruent (converse of corr. < post.)
2. show cons. int. < are supp. (conv. CIA theorem)
3. show alt. ext. < are congruent (conv. of AEA theorem)
4. show alt. int. < are congruent (conv. of AEA theorem)
5. show slopes are congruent
6. show their coplanar lines can never intersect

Front 15

slope intercept form

Back 15

y=mx+b

Front 16

standard form

Back 16

Ax+By=C

Front 17

point slope form

Back 17

y-y1=m(x-x1)
(y1 and x1 are the points the line intersects through)