IMO Practice Test — Lines and Angles
6 Questions • 12 min • Olympiad level
12:00
Question 1 of 6
hard
Four right angles together make…
a full turn (360°)
a straight angle
an obtuse angle
180°
Explanation: 4 × 90° = 360°, a full turn.
Question 2 of 6
hard
The hands of a clock at 6 o'clock form a…
straight angle
right angle
acute angle
full turn
Explanation: At 6:00 the hands point opposite ways → 180°.
Question 3 of 6
medium
Perpendicular lines always form an angle of…
90°
45°
180°
60°
Explanation: Perpendicular lines meet at 90°.
Question 4 of 6
hard
The opposite sides of a rectangle are…
parallel
perpendicular
curved
unequal
Explanation: Opposite sides of a rectangle are parallel.
Question 5 of 6
medium
An angle of 135° and an angle of 45° together make…
180°
90°
360°
120°
Explanation: 135 + 45 = 180°.
Question 6 of 6
hard
Two equal angles together make a right angle. Each angle is…
45°
90°
30°
60°
Explanation: 90 ÷ 2 = 45°.