Conjectures and Counter Examples
Line relationships
Proving Lines Parallel
Slopes of Parallel and Perpendicular Lines
100

Find the FIFTH term in the sequence 6,12,18...

30

100

What are two coplaner lines that do not intersect

Parallel Lines

100

If <A and <B are alternate interior angles, and <A=4x+10 and <B=6x-10, what value of x makes those lines parallel? 

x=10

100

If two lines are parallel, and line 1 have a slope of 3... what is line 2's slope? 

3

200
Is this true? If not, find a counter example: 

If <A and <B are complementary, then they are congruent. 

False! <A=40 <B=50

200

What are two lines that are not coplaner, do not intersect and are not parallel?

Skew Lines

200

If <W and <C are same side interior angles, and <W=3x+16 and <C=7x+4, what value of x makes these lines parallel?

x=16

200

If two lines are perpendicular, and line 1's slope is 4... what is line 2's slope? 

-1/4

300

Make a conjecture about the product of two odd numbers. 

The product of two odd numbers is an odd number.

300

What are angles that are on the exterior of parallel lines, on the opposite sides of the transversal? 

For DOUBLE points, how are these angles related?

Alternate Exterior

They are congruent! 

300

If <G and <Y are alternate exterior angles, and <G=35 and <Y=3x+5

x=10

300

Name a line parallel to y=3x+2. 

y=3x+(anything but 2!)

400

Find a counter example, for "All even numbers are positive"

-6

400

What are two lines that cross or touch at a point called? 

Intersecting Lines

400

If <K and <J are same side interior, and <K=2x+2 and <J=68, find the value of x that makes the lines parallel

x=33

400

Are y=-4/5x+3 and y=5x+4 parallel, perpendicular, or neither? 

neither! 

500

Find a counter example: 

All lines that never intersect are parallel. (HINT think 3D)

Skew Lines! 

500

On parallel lines, what are angles that are in the same location on the same side of the transversal? 

Corresponding Angles
500

are <B and <Z are corresponding angles, <B=7x-2 and <Z=2x+33, what value of x makes the lines parallel? 

x=7

500

Are Line AB and Line CD parallel, perpendicular, or neither? 

A(-6,8) B(-4,-2) and C(6,4) D(8,-6)

Parallel!

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