Class 8th Mathematics MCQ

Q1. How many measurements are required to construct a quadrilateral, uniquely?

1. Six

2. Four

3. Five

4. Three

Ans: 3. Five

Q2. The value of (x) in the following figure is:

1. 120°

2. 80°

3. 100°

4. 60°

Ans: 4. 60°

Q3. All the sides of a regular polygon are:

1. Unequal in length.

2. Parallel to each other.

3. Equal in length.

4. None of these.

Ans: 3. Equal in length.

Solution:

A regular polygon has all its sides equal in length and all its angles equal in measure.

Q4. The minimum number of dimensions needed to construct a rectangle is:

1. 2

2. 4

3. 3

4. 1

Ans: 1. 2

Q5. How many sides does a heptagon have?

1. 2

2. 4

3. 7

4. 5

Ans: 3. 7

Q6. A quadrilateral which has exactly one pair of parallel sides is called. 

1. A parallelogram

2. A rectangle

3. A trapezium

4. A kite

Ans: 3. A trapezium

Q7. Which of the following polygons is convex polygon?

.

Ans: 3.

Q8. The minimum number of measurements needed to construct a square is:

1. 1

2. 3

3. 2

4. 4

Ans: 1. 1

Q9. If n is the number of sides, then the number of diagonals of a polygon is:

1.

2.

3.

4.

Ans:

n(n – 3)

2

n(n – 3)

3

n

3n

2

1.

Solution:

For a quadrilateral, n = 4

Thus, a quadrilateral has two diagonals.

Q10. The sum of the angles in a quadrilateral is equal to _____.

1. 2 right angles.

2. 3 right angles.

3. 4 right angles.

4. 360 right angles.

Ans: 3. 4 right angles.

Q11. Polygons that have no portions of their diagonals in their exteriors are called.

1. Triangles

2. Convex

3. Concave

4. Squares

Ans: 1. Convex

Q12. A polygon with minimum number of sides is:

1. Pentagon

2. Square

3. Triangle

4. Angle

Ans: 3. Triangle

Q13. To construct a square, we need to know:

1. All the side lengths.

2. Only one interior angle.

3. Only one side length.

4. All the interior angles.

Ans: 3. Only one side length.

Solution:

A square has all its sides equal and all the interior angles measure 90 degrees. Hence, if the length of one side is known, then we can

construct a square easily.

Q14. A quadrilateral can be constructed uniquely if its two diagonals and _____ sides are known.

1. 1

2. 2

3. 3

4. None of these.

Ans: 3. 3

Q15. All the sides of a regular polygon are _________________.

1. Are equal

2. Parallel

3. Not equal

4. Not parallel

Ans: 1. Are equal

Q16. What do we require to construct a quadrilateral if lengths of four sides are given?

1. One of the angle.

2. Length of a diagonal.

3. Length of two diagonals.

4. None of these.

Ans: 2. Length of a diagonal.

Q17. The angles of quadrilateral are in the ratio 1 : 3 : 7 : 9. The measure of the largest angle is:

1. 63°

2. 72°

3. 81°

4. None of these.

Ans: 4. None of these.

Solution:

Let the angles be (x)°, (3x)°, (7x)° and (9x)° (x)°, (3x)°, (7x)° and (9x)°.

Sum of the angles of the quadrilateral is 360°.

x + 3x + 7x + 9x = 360

20x = 360

x = 18

Angles:

(3x)° = (3 × 18) = 54°

(7x)° = (7 × 18)° = 126°

(9x)° = (9 × 18)° = 162°

Q18. To construct a parallelogram, the minimum number of measurements required is:

1. 2

2. 3

3. 4

4. 1

Ans: 2. 3

Q19. The number of sides in a regular polygon is 15, then measure of each exterior angle is:

1. 24°

2. 36°

3. 20°

4. 18°

Ans: 1. 24°

Q20. To construct a parallelogram we need to know:

1. Two adjacent sides and one angle.

2. Measure of interior angles.

3. Two adjacent sides and two angles.

4. Length of its parallel sides.

Ans: 1. Two adjacent sides and one angle.

Solution:

Parallelogram has its parallel sides equal. Also, if one angle is known to us, then we can determine the other angle since the two

angles are supplementary.

Q21. What the point of intersection of the altitudes of a triangle called?

1. Circum centre

2. In centre

3. Centroid

4. Orthocentre

Ans: 4. Orthocentre

Q22. What the point of intersection of the medians of a triangle called?

1. Circum-centre

2. Incentre

3. Centroid

4. Orthocentre

Ans: 3. Centroid

Q23. How many faces a tetrahedron has?

1. 14

2. 12

3. 6

4. 4

Ans: 3. 6

Q24. The number of measurements required to construct a quadrilateral is:

1. 5

2. 4

3. 3

4. 2

Ans: 1. 5

Q25. To construct a rectangle, we need to know:

1. Only Length and breadth.

2. All the interior angles.

3. Only one angle measure.

4. All the Sides.

Ans: 1. Only Length and breadth.

Solution:

A rectangle has its parallel sides equal and all the interior angles measure 90 degrees. Hence, if the length and breadth rectangle is

known, then we can construct it easily.

Q26. If two diagonals and three sides are given, then:

1. Any polygon can be constructed.

2. A quadrilateral cannot be constructed.

3. Insufficient information.

4. A quadrilateral can be constructed.

Ans: 4. A quadrilateral can be constructed.

Q27. The value of x in the following figure is:

1. 100°

2. 90°

3. 108°

4. 120°

Ans: 3. 108°

Q28. The sum of exterior angles of a polygon is equal to:

1. 360º

2. 540º

3. 180º

4. 720º

Ans: 1. 360º

Solution:

The sum of exterior angles of any polygon is always equal to 360º.

Q29. To construct a quadrilateral, we need to know two adjacent side and _____ angles.

1. Two.

2. Three.

3. One.

4. All four angles.

Ans: 2. Three.

Q30. All the angles of a regular polygon are of ______________.

1. 90°

2. 60°

3. Equal measure

4. Equal length

Ans: 3. Equal measure

Q31. The sum of all the interior angles of a hexagon is:

1. 540º

2. 180º

3. 720º

4. 360º

Ans: 3. 720°

SOlution:

Number of sides in hexagon, n = 6

Sum of interior angles = (n – 2) x 180º

= (6 – 2) × 180º

= 720º

Q32. Mark against the correct answer:

Two opposite angles of a parallelogram are (3x – 2)° and (50 – x)°. The measures of all its angles are:

1. 97°, 83°, 97°, 83°

2. 37°, 143°, 37°, 143°

3. 76°, 104°, 76°, 104°

4. None of these.

Ans: 2. 37°, 143°, 37°, 143°

Solution:

Opposite angles of a parallelogram are equal.

3x – 2 = 50 – x

⇒ 3x + x = 50 + 2

⇒ 4x = 52

⇒ x = 13

Therefore, the first and the second angles are:

(3x – 2)° = (2 × 13 – 2)° = 37°

(50 – x)° = (50 – 13)° = 37°

Q33. To construct a quadrilateral, we need to know three sides and _____ included angles.

1. Two.

2. Three.

3. One.

4. All four angles.

∴

Ans: 1. Two.

Q34. The diagonals of a square bisect each other at ______________ angle.

1. Acute

2. Right

3. Obtuse

4. Reflex

Ans: 2. Right

Q35. Polygons that have any portions of their diagonals in their exteriors are called.

1. Squares

2. Triangles

3. Convex

4. Concave

Ans: 4. Concave

Q36. What the name of the polyhedron is whose base & top are congruent polygons & whose lateral faces are

parallelograms in shape?

1. Tetrahedron

2. Trapezium

3. Prism

4. Parallelogram

Ans: 3. Prism

Q37. A parallelogram each of whose angles measures 90° is ______________.

1. Rectangle

2. Rhombus

3. Kite

4. Trapezium

Ans: 1. Rectangle

Q38. How many measurements can determine a quadrilateral uniquely?

1. 2

2. 3

3. 4

4. 5

Ans: 4. 5

Q39. How many diagonals does a regular Hexagon has?

1. 2

2. 9

3. 3

4. 5

Ans: 2. 9

Q40. Which of the following statements is true?

1. The diagonals of a rectangle are perpendicular.

2. The diagonals of a rhombus are equal.

3. Every square is a rhombus.

4. None of these.

Ans: 3. Every square is a rhombus.

Q41. If the lengths of two diagonals if a rhombus are 12cm and 16cm, then the length of each side of the rhombus is:

1. 10cm

2. Cannot be determined.

3. 14cm

4. None of these.

Ans: 1. 10cm

Q42. A quadrilateral can be constructed uniquely if its three sides and _____ included angles are given.

1. 1

2. 2

3. 3

4. None of these.

Ans: 2. 2

Q43. Which of the following is a three dimensional figure?

1. Square

2. Trapezium

3. Cube

4. Parallelogram

Ans: 3. Cube

Q44. the diagonals of a rhombus bisect each other at ______________ angles.

1. Acute

2. Right

3. Obtuse

4. Reflex

Ans: 2. Right