# CBSE Class 9 Maths Extra Questions: Chapter 8 - Quadrilaterals (with Answers)

CBSE Class 9 Maths extra questions and answers for Chapter 8 - Quadrilaterals are important exam preparations. All these questions are based on important concepts given in the chapter that students must be aware of to deal with different types of questions asked in exams. All these questions are provided with answers. Students must use this question bank for self-assessment and increase their chances of scoring high in exams.

**CBSE Class 9 Maths Extra Questions for Chapter 8 - Quadrilaterals****:**

**1. The diagonals of a _______ are equal and bisect each other at 90°?**

**Answer:**

The diagonals of a __square__ are equal and bisect each other at 90°.

**2. If one angle of a parallelogram is 75 ^{o}, then find its other three angles.**

**Answer:**

The remaining three angles will be 105^{o}, 75^{o} and 105^{o}.

Hint: In a parallelogram, opposite angles are equal.

**3. In a rectangle ABCD, one diagonal is inclined to one of its sides at 25° as shown in the following figure. Find ****∠AOB**** .**

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**Answer:**

∠AOB = 130^{o}

Hint: Diagonals of a rectangle divide the rectangle into two congruent right triangles

**4. If the bisectors of all four angles of a parallelogram are made to intersect each other then the new quadrilateral thus formed will be a:**

**(a) Rhombus**

**(b) Rectangle**

**(c) Square**

**(d) Parallelogram**

**Answer:**

(b) Rectangle

**5. A square is a special type of**

**(a) Rectangle**

**(b) Rhombus**

**(c) Parallelogram**

**(d) All of the above**

**Answer:**

(d) All of the above

**Also Check: **

**NCERT Solutions for Class 9 Maths**

**6. Two diagonals of a rhombus ABCD are intersecting each other at point O. What is the value of ****∠****DOC?**

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**

**Answer:**

∠DOC = 90^{o } (The diagonals of a rhombus are perpendicular to each other.)

**7. Which quadrilateral is formed by the angle bisectors of a parallelogram?**

**Answer:**

The angle bisectors of a parallelogram form a rectangle.

**8. Which of the following is/are the necessary condition(s) for a quadrilateral to be a parallelogram?**

**(a) Its diagonals bisect each other.**

**(b) Opposite angles are equal.**

**(c) Opposite sides are equal and parallel to each other**

**(d) All of the above**

**Answer:**

(d) All of the above

**9. Name the quadrilateral formed by joining the mid-points of all four sides of a rectangle.**

**Answer:**

Rhombus is the quadrilateral formed by joining the mid-points of all four sides of a rectangle.

**10. What type of triangle is formed by joining the mid-points of all three sides of an equilateral triangle?**

**(a) Isosceles **

**(b) Equilateral **

**Answer:**

(b) Equilateral

Equilateral triangle is formed by joining the mid-points of all three sides of an equilateral triangle.

Students must go through the latest CBSE Syllabus for Class 9 Maths so that they can prepare according to the contents prescribed by the board.

**Also check:**

**CBSE Class 9 Maths Important Questions and Answers**

**CBSE Class 9 Maths Important MCQ (Chapter-wise)**