26. Two lines with slopes m1 and m2 are parallel when:
- m1 m2 = -1
- m1 + m2 = 0
- m1 m2 = 1
- m1 = m2
Answer: D) m1 = m2
Explanation: Equal slopes give tantheta = 0, so theta = 0^circ. SLO M-09-B-10 · Knowledge
MCQs / Mathematics / Angle Between Lines
63 multiple-choice questions on Angle Between Lines from Mathematics, each with the correct answer and, where available, a teacher's explanation. Read through them to revise the chapter, then practise the same questions one by one to test yourself.
Answer: D) m1 = m2
Explanation: Equal slopes give tantheta = 0, so theta = 0^circ. SLO M-09-B-10 · Knowledge
Answer: A) 158
Explanation: Slopes: mAB = 14, mAC = 4. Using tan A = mAC - mAB1 + mABmAC (with the sign that gives the interior angle) we get tan A = 158. SLO M-09-B-12 · Knowledge
Answer: D) y = -2
Explanation: The lines meet at (3, -2); a line parallel to the x-axis through it is y = -2. SLO M-09-B-11 · Understanding
Answer: A) obtuse
Explanation: tantheta < 0 for 90^circ < theta < 180^circ. SLO M-09-B-12 · Knowledge
Answer: C) 90^circ
Explanation: Slopes m1 = 2, m2 = - 12. m1 m2 = -1, so theta = 90^circ. SLO M-09-B-10 · Knowledge
Answer: D) parallel
Explanation: theta = 0^circ means the lines are parallel (or the same). SLO M-09-B-10 · Knowledge
Answer: D) 60^circ
Explanation: tantheta = 3, so theta = 60^circ. SLO M-09-B-10 · Knowledge
Answer: A) 45^circ
Explanation: tantheta = m2 - m11 + m1 m2 = 52 52 = 1, so theta = 45^circ. SLO M-09-B-10 · Knowledge
Answer: C) 7
Explanation: tantheta = m2 - m11 + m1 m2 = - 72- 12 = 7. SLO M-09-B-10 · Knowledge
Answer: D) 45^circ
Explanation: tantheta = m2 - m11 + m1 m2 = - 2528 2528 = 1, so theta = 45^circ. SLO M-09-B-10 · Knowledge
Answer: B) 45^circ
Explanation: Slopes m1 = 1, m2 = 0. tantheta = 1, so theta = 45^circ. SLO M-09-B-10 · Knowledge
Answer: B) 2
Explanation: Slopes: mAB = 0, mAC = 2. Using tan A = mAC - mAB1 + mABmAC (with the sign that gives the interior angle) we get tan A = 2. SLO M-09-B-12 · Knowledge
Answer: B) 90^circ, 45^circ, 45^circ
Explanation: Slopes 1 and -1 are perpendicular; a vertical side makes 45^circ with each of them. SLO M-09-B-12 · Knowledge
Answer: D) 34
Explanation: Slopes: mAB = 0, mAC = 34. Using tan A = mAC - mAB1 + mABmAC (with the sign that gives the interior angle) we get tan A = 34. SLO M-09-B-12 · Knowledge
Answer: D) 45^circ
Explanation: Slopes m1 = 3, m2 = 12. tantheta = 1, so theta = 45^circ. SLO M-09-B-10 · Knowledge
Answer: C) (1, 4)
Explanation: Solve the two equations together: x = 1, y = 4. Check: both equations are satisfied by (1, 4). SLO M-09-B-11 · Understanding
Answer: A) (3, 1)
Explanation: The first two meet at (3, 1), and 2(3) + 1 = 7, so all three pass through (3, 1). SLO M-09-B-11 · Understanding
Answer: A) 3
Explanation: Slopes: mAB = 0, mAC = 3. Using tan A = mAC - mAB1 + mABmAC (with the sign that gives the interior angle) we get tan A = 3. SLO M-09-B-12 · Knowledge
Answer: A) (3, -2)
Explanation: Solve the two equations together: x = 3, y = -2. Check: both equations are satisfied by (3, -2). SLO M-09-B-11 · Understanding
Answer: D) 90^circ, 45^circ, 45^circ
Explanation: AB is horizontal and AC vertical, so angle A = 90^circ; BC has slope -1, giving 45^circ at B and C. SLO M-09-B-12 · Knowledge
Answer: D) x - y + 3 = 0
Explanation: The lines meet at (1, 4). The line through (1, 4) and (0, 3) is x - y + 3 = 0 (you can also use L1 + kL2 = 0 and find k from the point). SLO M-09-B-11 · Understanding
Answer: D) 3
Explanation: Slopes: mAB = 0, mAC = 3. Using tan A = mAC - mAB1 + mABmAC (with the sign that gives the interior angle) we get tan A = 3. SLO M-09-B-12 · Knowledge
Answer: D) x - 2y = 0
Explanation: The lines meet at (2, 1). The line through (2, 1) and (0, 0) is x - 2y = 0 (you can also use L1 + kL2 = 0 and find k from the point). SLO M-09-B-11 · Understanding
Answer: B) 7
Explanation: tantheta = m2 - m11 + m1 m2 = - 73 13 = 7. SLO M-09-B-10 · Knowledge
Answer: A) 2
Explanation: Slopes: mAB = 0, mAC = 2. Using tan A = mAC - mAB1 + mABmAC (with the sign that gives the interior angle) we get tan A = 2. SLO M-09-B-12 · Knowledge
Practise Angle Between Lines MCQs