Olympiad – Class IX – Mathematics - Lines and Angles

Buy Olympiad -IX Standard Practice test pack

Question - 1

The measure of an angle is four times the measure of its supplement. Identify the angles.

  • A 36°,144°
  • B 40°,160°
  • C 18°, 72°
  • D 50°, 200°

Question - 2

If two supplementary angles are in the ratio 4 : 5, find the angles

  • A 80°, 100°
  • B 85°,95°
  • C 40°, 50°
  • D 60°, 120°

Question - 3

From the given figure, find the value of y° when X° = 30°.

  • A 25°
  • B 24°
  • C 36°
  • D 45°

Question - 4

From the figure given, if \(\angle\) POR and \(\angle\) QOR form a linear pair and a - b = 40°, what are the respective values of a and b?

  • A 110°,70°
  • B 70°,100°
  • C 80°,120°
  • D 120°,80°

Question - 5

From the figure given, find the value of x, if BC || ED

  • A 85°
  • B 90°
  • C 95°
  • D 80°

Question - 6

In \(\triangle\)ABC, \(\angle \) A\({\angle B\over 2}={\angle C \over6}\) . Find the measure of \(\angle \) A.

  • A 60°
  • B 30°
  • C 40°
  • D 20°

Question - 7

The sides BC, CA and AB of \(\triangle\)ABC are produced in order to form exterior angles \(\angle \)ACO, \(\angle \) BAE and \(\angle \) CBF.

Find \(\angle \)ACO +\(\angle \) BAE +\(\angle \) CBF.

  • A 180°
  • B 270°
  • C 360°
  • D 540°

Question - 8

In the given figure, BO and CO are angle bisectors of external angles of \(\triangle\) ABC. Find \(\angle \) BOC

  • A 90° -\({1\over2}\) \(\angle \) A
  • B 90° +\({1\over2}\) \(\angle \) A
  • C 1800-\({1\over2}\) \(\angle \) A
  • D 1800+\({1\over2}\) \(\angle \) A

Question - 9

In the figure, the bisectors of Band C meet at O. Find the measure of  \(\angle \) BOC

  • A 90° -\({1\over2}\) \(\angle \) A
  • B 90° +\({1\over2}\) \(\angle \) B
  • C 90° +\({1\over2}\) \(\angle \) C
  • D 90° +\(\angle \)A

Question - 10

From the given figure, find the value of x.

  • A 60°
  • B 75°
  • C 90°
  • D 120°