10 questions · Form 1 Mathematics Bab 9: Basic Polygons
How many diagonals does a hexagon have?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. How many diagonals does a hexagon have?
Answer: C
For a hexagon, n = 6. Diagonals = 66 - 32 = 632 = 9.
2. What is the formula to calculate the number of diagonals in an n-sided polygon?
Answer: B
The formula to determine the total number of diagonals in an n-sided polygon is nn - 32.
3. In an isosceles triangle ABC where AB = AC, if the vertex angle A is 40°, calculate the measure of base angle B.
Answer: A
Base angles are equal. Sum = 180°. Angle B = 180° - 40°2 = 140° / 2 = 70°.
4. An exterior angle of a triangle is 115°, and one of its opposite interior angles is 45°. Find the other opposite interior angle.
Answer: B
An exterior angle equals the sum of two opposite interior angles: 115° = 45° + interior angle => interior angle = 115° - 45° = 70°.
5. Which quadrilateral has ONLY ONE pair of parallel sides?
Answer: C
By definition, a trapezium is a quadrilateral with only one pair of parallel sides.
6. What is the sum of interior angles of any quadrilateral?
Answer: C
Every quadrilateral can be divided into two triangles, making the sum of its interior angles 2 × 180° = 360°.
7. Three interior angles of a quadrilateral are 85°, 110°, and 95°. Calculate the fourth angle.
Answer: B
Sum of quadrilateral angles = 360°. Fourth angle = 360° - (85° + 110° + 95°) = 360° - 290° = 70°.
8. Which triangle has 3 lines of symmetry and all interior angles equal to 60°?
Answer: C
An equilateral triangle has 3 equal sides, 3 equal angles of 60°, and 3 lines of symmetry.
9. If a triangle has angle measurements of 35°, 55°, and 90°, what type of triangle is it?
Answer: C
Because one interior angle measures exactly 90°, it is classified as a right-angled triangle.
10. If the angles of a triangle are in the ratio 1 : 2 : 3, find the largest angle.
Answer: C
Total parts = 1 + 2 + 3 = 6. Total angle = 180°. Each part = 180° / 6 = 30°. Largest angle = 3 × 30° = 90°.