IMO Practice Test — Points, Lines, Rays, Angles
6 Questions • 10 min • Olympiad level
10:00
Question 1 of 6
hard
How many right angles does a square have?
2
3
4
8
Explanation: A square has 4 corners, each a right angle (90°).
Question 2 of 6
hard
Is 89° an acute or obtuse angle?
Acute (less than 90°)
Right (exactly 90°)
Obtuse (more than 90°)
Cannot tell
Explanation: 89° is just less than 90°, so it is an acute angle.
Question 3 of 6
hard
Is 91° an acute or obtuse angle?
Acute
Right
Obtuse
Flat
Explanation: 91° is just more than 90°, so it is an obtuse angle.
Question 4 of 6
hard
A clock at 3:00 — what angle do the hands form?
Acute
Right (90°)
Obtuse
Flat (180°)
Explanation: At 3:00 the minute hand points at 12 and hour hand at 3 — making a perfect right angle (90°).
Question 5 of 6
hard
A clock at 5:00 — what type of angle do the hands form?
Acute
Right
Obtuse (150°)
Flat
Explanation: At 5:00 the angle between hands is 150° (5 x 30° per hour), which is obtuse.
Question 6 of 6
hard
How many angles in a triangle?
2
3
4
6
Explanation: A triangle has 3 sides and 3 angles.