Parallel and Intersecting Lines — Practice

Q1. When a pair of lines on a plane surface meet each other at a point, the lines are said to

• A. Be parallel to each other.
• B. Intersect each other.
• C. Be perpendicular to each other.
• D. Form a single straight line.

Q2. When two straight lines intersect each other on a plane, how many angles are formed at the point of intersection?

• A. Two
• B. Four
• C. Six
• D. Eight

Q3. Can two straight lines on a plane intersect at more than one point?

• A. Yes, at two points.
• B. Yes, at any number of points.
• C. No, only at one point.
• D. Only if both are perpendicular.

Q4. Two adjacent angles formed by two intersecting lines are called a linear pair. Their measures always add up to

• A. 90°
• B. 180°
• C. 270°
• D. 360°

Q5. When two lines intersect, the pair of opposite angles formed (called vertically opposite angles) are

• A. Supplementary (sum 180°).
• B. Always equal to each other.
• C. Always 90° each.
• D. Complementary (sum 90°).

Q6. In Fig. 5.2, lines l and m intersect at a point. If ∠a is 120°, what is the measure of the adjacent angle ∠b?

• A. 120°
• B. 30°
• C. 60°
• D. 90°

Q7. Perpendicular lines are a pair of lines which intersect each other at

• A. Right angles (90°).
• B. Acute angles only.
• C. Obtuse angles only.
• D. Any angle, but only at the midpoint.

Q8. Two lines intersect such that all four angles formed are equal. Each angle must measure

• A. 45°
• B. 60°
• C. 90°
• D. 180°

Q9. Which of the following is the correct definition of parallel lines?

• A. Lines that lie on the same plane and meet at a single point.
• B. Lines that lie on the same plane and do not meet however far they are extended at both ends.
• C. Lines that lie on different planes and never meet.
• D. Lines that intersect at right angles.

Q10. In mathematics, which mark is used on a set of lines to show that they are parallel to each other?

• A. A small square at the intersection.
• B. A short single dash on each line.
• C. An arrow mark (>) on each line.
• D. A small circle on each line.

Q11. A line that intersects two different lines is called

• A. A transversal.
• B. A bisector.
• C. A perpendicular.
• D. A diagonal.

Q12. When a transversal crosses a pair of lines, how many angles are formed in total at the two intersection points?

• A. Four
• B. Six
• C. Eight
• D. Ten

Q13. In Fig. 5.14, when a transversal t intersects lines l and m, angle ∠1 (at line l) and ∠5 (at line m) are at matching positions. Such a pair is called

• A. Vertically opposite angles.
• B. Linear pair.
• C. Corresponding angles.
• D. Alternate angles.

Q14. When a transversal intersects a pair of parallel lines, the corresponding angles formed are

• A. Always supplementary (sum 180°).
• B. Always equal to each other.
• C. Always 90° each.
• D. Always complementary (sum 90°).

Q15. When a transversal intersects a pair of parallel lines, the alternate angles formed are

• A. Always equal to each other.
• B. Always supplementary (sum 180°).
• C. Always 90° each.
• D. Always in the ratio 1:2.