IMO Practice Test — Classifying 2D Figures
6 Questions • 25 min • Olympiad level
25:00
Question 1 of 6
hard
A polygon has 10 sides. It is called a…
decagon
octagon
heptagon
nonagon
Explanation: 10 sides = decagon.
Question 2 of 6
medium
Which shape always has 4 right angles AND 4 equal sides?
square
rectangle
parallelogram
rhombus
Explanation: Only the square guarantees both.
Question 3 of 6
hard
Which triangle has NO line of symmetry?
equilateral
isosceles
scalene
all have one
Explanation: A scalene triangle (all sides different) has no line of symmetry.
Question 4 of 6
medium
A triangle has angles 50° and 60°. The third angle is…
60°
70°
80°
90°
Explanation: 180 − 50 − 60 = 70°.
Question 5 of 6
medium
A parallelogram with 4 right angles is a…
rectangle
triangle
trapezium
pentagon
Explanation: Right angles make a parallelogram into a rectangle.
Question 6 of 6
hard
Which shape has endless (infinite) lines of symmetry?
square
circle
triangle
rectangle
Explanation: A circle has infinitely many lines of symmetry.