State whether the following statement is always true, sometimes true, or never true:

Supplementary angles form a linear pair.

A. Always true because a linear pair of angles are supplementary by definition.
Incorrect. Some pairs of supplementary angles are not adjacent as linear pair angles must be.

B. Sometimes true because it is true when the angles share a common side.
Correct!

C. Sometimes true because a linear pair of angles cannot be complimentary.
Incorrect. Irrelevant. You are trying to evaluate whether every pair of supplementary angles form a linear pair.

D. Never true.
Incorrect. There are cases for which this statement is true.

Which of the following describes a method of forming a conjecture based on examples?

A. Deductive reasoning
Incorrect. This uses facts and true statements to prove a conjecture.

B. Inductive reasoning
Correct!

C. Counter example
Incorrect. This disproves a conjecture.

D. Contrapositive
Incorrect. This is a variation on a given statement.

For which statement will a counter example prove the statement false?

A. All squares are parallelograms.
Incorrect. This statement is always true.

B. All rectangles are squares.
Correct! There are some rectangles which are not squares.

C. All parallelograms are quadrilaterals.
Incorrect. This statement is always true.

D. All trapezoids are not parallelograms.
Incorrect. This statement is always true.

Which of the following is a counter example for the statement below?

If you have two lines, the lines will always intersect in one point.

A. If two lines are parallel they do not intersect at all.
Correct!

B. Two parallel lines cut by a transversal form 2 points of intersection.
Incorrect. Irrelevant to talk about 3 lines.

C. Lines which intersect are coplanar.
Incorrect. True, but irrelevant.

D. It takes two points to determine a line.
Incorrect. True, but irrelevant.