Geometry Parallel Lines & Transversals 3

Question 1

A transversal cuts two parallel lines. One angle measures 70°. What is its alternate exterior angle?

Accepted Answer

70°

Answer

Alternate exterior angles are congruent when lines are parallel, so the alternate exterior angle also measures 70°.

Question 2

Lines l and m are parallel, cut by transversal t. One angle is (4x − 10)° and its corresponding angle is (2x + 40)°. Find x.

Accepted Answer

25

Answer

Corresponding angles are equal: 4x − 10 = 2x + 40, so 2x = 50 and x = 25.

Question 3

Which of the following does NOT prove that two lines cut by a transversal are parallel?

Accepted Answer

Corresponding angles are supplementary

Answer

Corresponding angles must be equal (not supplementary) to prove lines are parallel; supplementary corresponding angles do not guarantee parallelism.

Question 4

If a transversal is perpendicular to one of two parallel lines, it is _____ perpendicular to the other.

Accepted Answer

always

Answer

Because corresponding angles are equal for parallel lines, a 90° angle at one intersection means a 90° angle at the other — the transversal is always perpendicular to both.

Question 5

Two parallel lines are cut by a transversal. One co-interior angle is 3 times the other. Find the smaller angle.

Accepted Answer

45°

Answer

Let the smaller angle be x; then x + 3x = 180°, so 4x = 180° and x = 45°.

Geometry Practice Test

Geometry Practice Test

Geometry Parallel Lines & Transversals 3