Question

Which of the following is a condition for the figure below that will not prove l1 is parallel to l2

Answer 1

D.

`\measuredangle a+\measuredangle c=180^0`

Step-by-step explanation:

Given the line l1 and l2. as shown in the figure below.

We want to find the rule that will not prove line l1 is parallel to l2;

Let us examine each of the conditions;

A. angle b congruent to angle d.

This proves that the two line are parallel.

Reason; Corresponding angles

B. angle b plus angle a equals 180 degree.

This condition also prove that the two lines are parallel.

Reason: Angle b equals angle d, angle d and angle a are supplementary angles.

C. angle c is congruent to angle b.

This condition also prove that the two lines are parallel.

D. Angle a plus angle c equals 180 degree.

This condition does not relate line l1 to line l2.

So, it does not prove that line l1 and l2 are parallel.