# CBSE Class 9 Maths Exam 2020-21: NCERT Based Extra Questions (With Answers) - Chapter 7 Triangles

**CBSE: **Check important extra questions for the upcoming CBSE Class 9 Maths exam 2020-21 from Chapter 7 Triangles of Class 9 Maths NCERT textbook. Answers to all the problems are also available here. Students with sound knowledge of basic concepts of this chapter can easily attempt the questions in less than 5 minutes. These questions might be also asked in CBSE School examinations with a little modification.

**CBSE Class 9 Maths Exam 2020-21: Extra Questions (With Answers) - Chapter 7 Triangles**

**Question:** The sides opposite to equal angles of a triangle

(i) might be equal

(ii) are always equal

(iii) are always unequal

(iv) are unpredictable in length

**Answer: **(ii)

The sides opposite to equal angles of a triangle are always equal.

CBSE Class 9 Revised Syllabus for 2020-2021

**Question: **ABC is an isosceles triangle with AB = AC. Suppose there is a point P such that AP ⊥ BC then

(i) ∠ B ≠ ∠ C

(ii) ∠ B = ∠ C

(iii) ∠ B > ∠ C

(iv) ∠ B < ∠ C.

**Answer: **(ii)

ABC is an isosceles triangle with AB = AC. P is a point such that if AP ⊥ BC then ∠ B = ∠ C. *(NCERT textbook Class 9 Maths NCERT EXERCISE 7.3, Question 5)*

**Question**: Read the following statement.

If two sides of a triangle are unequal, the angle opposite to the ______ side is ______.

The correct option to fill in the blanks is

(i) longer, unpredictable

(ii) shorter, longer

(iii) longer, shorter

(iv) longer, larger

**Answer:** (iv)

If two sides of a triangle are unequal, the angle opposite to the longer side is larger (or greater).

**Questions: **If ∆ MNO ≅ ∆ PQR Mnd ∆ MNO is not congruent to ∆ RPQ, then which of the following is not true:

(i) NO = PQ (ii) MO = PR (iii) QR = NO (iv) MN = PQ

**Answer:** (i)

**Question:** In triangles MNC and DEF, ∠M = ∠D, ∠N = ∠E and MN = EF. Will the two triangles be congruent? Give reasons for your answer.

**Answer: **Two triangles need not be congruent, because MN and EF are not corresponding sides in the two triangles.

**Question**: Complete the sentence given below

Two figures are congruent if they are of the _____________________.

**Answer:**

Two figures are congruent if they are of the same shape and the same size.

**Question: **What is the value of each angle in an equilateral triangle?

**Answer: **

60 Degree.

**Question:** which of the following options in relation with a triangle ABC is correct?

(i) AB + BC > AC

(ii) BC + CA > AB

(iii) AB + AC > BC

(iv) All (i), (ii), (iii) are correct

**Answer: (iv)**

It is because, in a triangle, the sum of any two sides of a triangle is greater than the third side.

**Question: **In a right angled triangle, the greatest side is known as the _______.

**Answer:** Hypotenuse.

**Question: **All the angles of a triangle with a side of length 2 cm are equal. Find its other two sides.

**Answer:**

As all the angles of a triangle are equal so it is an equilateral triangle. It means all the sides of this triangle are equal. So, it means the lengths of all sides are equal. Which means each side is equal to 2 cm.

**NCERT Solutions for Class 9 - Maths, Science, Social Science and English (Chapter-Wise PDF)**