Class 8 Maths MCQs on Angle Sum Property and Interior Angles of Polygons
Class 8 Maths MCQs on Angle Sum Property and Interior Angles of Polygons
Class: 8
Subject: Mathematics
Chapter 4: Quadrilaterals
Topic: Angle Sum Property & Interior Angles of Polygons
Subject: Mathematics
Chapter 4: Quadrilaterals
Topic: Angle Sum Property & Interior Angles of Polygons
Strictly Based on CBSE Curriculum | As per NCERT Textbook | Ideal for CBSE Class 8 Examination Preparation
Q1. The sum of interior angles of a quadrilateral is:
Correct Answer: B) 360°
Explanation: A quadrilateral can be divided into two triangles. Each triangle has 180°, so total = 180° + 180° = 360°.
Explanation: A quadrilateral can be divided into two triangles. Each triangle has 180°, so total = 180° + 180° = 360°.
Q2. The sum of interior angles of a pentagon is:
Correct Answer: B) 540°
Explanation: Formula: (n−2) × 180°. For pentagon (5−2) × 180° = 3 × 180° = 540°.
Explanation: Formula: (n−2) × 180°. For pentagon (5−2) × 180° = 3 × 180° = 540°.
Q3. The sum of interior angles of a hexagon is:
Correct Answer: A) 720°
Explanation: (6−2) × 180° = 4 × 180° = 720°.
Explanation: (6−2) × 180° = 4 × 180° = 720°.
Q4. Formula for sum of interior angles of n-sided polygon:
Correct Answer: C) (n−2) × 180°
Explanation: Derived by dividing polygon into (n−2) triangles.
Explanation: Derived by dividing polygon into (n−2) triangles.
Q5. Each interior angle of a regular quadrilateral is:
Correct Answer: B) 90°
Explanation: Regular quadrilateral is square; 360° ÷ 4 = 90°.
Explanation: Regular quadrilateral is square; 360° ÷ 4 = 90°.
Q6. Each interior angle of regular pentagon is:
Correct Answer: A) 108°
Explanation: 540° ÷ 5 = 108°.
Explanation: 540° ÷ 5 = 108°.
Q7. If sum of angles of polygon is 900°, number of sides is:
Correct Answer: B) 7
Explanation: (n−2) × 180 = 900 → n−2 = 5 → n=7.
Explanation: (n−2) × 180 = 900 → n−2 = 5 → n=7.
Q8. Each interior angle of regular hexagon is:
Correct Answer: A) 120°
Explanation: 720° ÷ 6 = 120°.
Explanation: 720° ÷ 6 = 120°.
Q9. The sum of interior angles of a triangle is:
Correct Answer: B) 180°
Explanation: Basic triangle property.
Explanation: Basic triangle property.
Q10. If one angle of quadrilateral is 90° and others are 80°, 100°, the fourth angle is:
Correct Answer: B) 90°
Explanation: Total 360° − (90+80+100)= 90°.
Explanation: Total 360° − (90+80+100)= 90°.
Q11. Each interior angle of regular octagon is:
Correct Answer: B) 135°
Explanation: (8−2)×180=1080; 1080÷8=135°.
Explanation: (8−2)×180=1080; 1080÷8=135°.
Q12. Sum of angles of decagon is:
Correct Answer: A) 1440°
Explanation: (10−2)×180=8×180=1440°.
Explanation: (10−2)×180=8×180=1440°.
Q13. If each interior angle is 150°, polygon has sides:
Correct Answer: B) 12
Explanation: (n−2)×180/n=150; solving gives n=12.
Explanation: (n−2)×180/n=150; solving gives n=12.
Q14. Each angle of regular triangle is:
Correct Answer: A) 60°
Explanation: 180° ÷ 3 = 60°.
Explanation: 180° ÷ 3 = 60°.
Q15. If sum of interior angles is 720°, polygon is:
Correct Answer: B) Hexagon
Explanation: (n−2)×180=720 → n=6.
Explanation: (n−2)×180=720 → n=6.
Q16. Exterior angle of regular hexagon is:
Correct Answer: A) 60°
Explanation: Exterior angle = 360° ÷ 6 = 60°.
Explanation: Exterior angle = 360° ÷ 6 = 60°.
Q17. Interior + exterior angle of polygon equals:
Correct Answer: B) 180°
Explanation: They form a linear pair.
Explanation: They form a linear pair.
Q18. A polygon with 9 sides is:
Correct Answer: A) Nonagon
Explanation: 9-sided polygon is called nonagon.
Explanation: 9-sided polygon is called nonagon.
Q19. A quadrilateral can be divided into how many triangles?
Correct Answer: B) 2
Explanation: Draw one diagonal to form two triangles.
Explanation: Draw one diagonal to form two triangles.
Q20. Each interior angle of regular decagon is:
Correct Answer: B) 144°
Explanation: 1440° ÷ 10 = 144°.
Explanation: 1440° ÷ 10 = 144°.
