IMO Geometry 1 — Questions and Answers
Question 1: What is the sum of interior angles of a triangle?
- 90°
- 180° (Correct answer)
- 270°
- 360°
Correct answer: 180°
The interior angles of any triangle always add up to 180°.
Question 2: A rectangle has a length of 12 cm and a width of 5 cm. What is its perimeter?
- 34 cm (Correct answer)
- 60 cm
- 17 cm
- 24 cm
Correct answer: 34 cm
Perimeter = 2 × (length + width) = 2 × (12 + 5) = 2 × 17 = 34 cm.
Question 3: A circle has a radius of 7 cm. What is its area? (Use π ≈ 22/7)
- 154 cm² (Correct answer)
- 44 cm²
- 98 cm²
- 77 cm²
Correct answer: 154 cm²
Area = π × r² = (22/7) × 7² = (22/7) × 49 = 154 cm².
Question 4: Which of the following is a property of an equilateral triangle?
- One angle is 90°
- All sides are equal (Correct answer)
- Two sides are equal
- No sides are equal
Correct answer: All sides are equal
An equilateral triangle has all three sides equal and all three angles equal to 60°.
Question 5: What is the area of a triangle with base 10 cm and height 6 cm?
- 60 cm²
- 30 cm² (Correct answer)
- 16 cm²
- 32 cm²
Correct answer: 30 cm²
Area of a triangle = (1/2) × base × height = (1/2) × 10 × 6 = 30 cm².
Question 6: How many lines of symmetry does a square have?
- 2
- 4 (Correct answer)
- 6
- 8
Correct answer: 4
A square has 4 lines of symmetry: two along the diagonals and two along the midpoints of opposite sides.
IMO Geometry 1
What is the sum of interior angles of a triangle?