## MCQ Questions for Class 9 Maths Chapter 7 Triangles with Answers

MCQs from Class 9 Maths Chapter 7 – Triangles are provided here to help students prepare for their upcoming Maths exam.

MCQs from CBSE Class 9 Maths Chapter 7: Triangles

**Q1. If E and F are the midpoints of equal sides AB and AC of a triangle ABC. Then:**

a) BF=AC

b) BF=AF

c) CE=AB

d) BF = CE

**Answer/Explanation**

Answer: (d)

Explanation: AB and AC are equal sides.

AB = AC (Given)

∠A = ∠A (Common angle)

AE = AF (Halves of equal sides)

∆ ABF ≅ ∆ ACE (By SAS rule)

Hence, BF = CE (CPCT)

**Q2. ABC is an isosceles triangle in which altitudes BE and CF are drawn to equal sides AC and AB respectively. Then:**

a) BE>CF

b) BE<CF

c) BE=CF

d) None of the above

**Answer/Explanation:**

Answer: (c)

Explanation:

∠A = ∠A (common arm)

∠AEB = ∠AFC (Right angles)

AB = AC (Given)

∴ ΔAEB ≅ ΔAFC

Hence, BE = CF (by CPCT)

**Q3. If ABC and DBC are two isosceles triangles on the same base BC. Then:**

a) ∠ABD = ∠ACD

b) ∠ABD > ∠ACD

c) ∠ABD < ∠ACD

d) None of the above

**Answer/Explanation**

Answer: (a)

Explanation: AD = AD (Common arm)

AB = AC (Sides of isosceles triangle)

BD = CD (Sides of isosceles triangle)

So, ΔABD ≅ ΔACD.

∴ ∠ABD = ∠ACD (By CPCT)

**Q4. If ABC is an equilateral triangle, then each angle equals to:**

a) 90°

B)180°

c) 120°

d) 60°

**Answer/Explanation**

Answer: (d)

Explanation: Equilateral triangle has all its sides equal and each angle measures 60°.

AB= BC = AC (All sides are equal)

Hence, ∠A = ∠B = ∠C (Opposite angles of equal sides)

Also, we know that,

∠A + ∠B + ∠C = 180°

⇒ 3∠A = 180°

⇒ ∠A = 60°

∴ ∠A = ∠B = ∠C = 60°

**Q5. If AD is an altitude of an isosceles triangle ABC in which AB = AC. Then:**

a) BD=CD

b) BD>CD

c) BD<CD

d) None of the above

**Answer/Explanation**

Answer: (c)

Explanation: In ΔABD and ΔACD,

∠ADB = ∠ADC = 90°

AB = AC (Given)

AD = AD (Common)

∴ ΔABD ≅ ΔACD (By RHS congruence condition)

BD = CD (By CPCT)

**Q6. In a right triangle, the longest side is:**

a) Perpendicular

b) Hypotenuse

c) Base

d) None of the above

**Answer/Explanation**

Answer: (b)

Explanation: In triangle ABC, right-angled at B.

∠B = 90

By angle sum property, we know:

∠A + ∠B + ∠C = 180

Hence, ∠A + ∠C = 90

So, ∠B is the largest angle.

Therefore, the side (hypotenuse) opposite to largest angle will be longest one.

**Q7. In triangle ABC, if AB=BC and ∠B = 70, ∠A will be:**

a) 70

b) 110

c) 55

d) 130

**Answer**

Answer: (c)

Explanation: Given,

AB = BC

Hence, ∠A=∠C

And ∠B = 70

By angle sum property of triangle we know:

∠A+∠B+∠C = 180

2∠A+∠B=180

2∠A = 180-∠B = 180-70 = 110

∠A = 55

**Q8. For two triangles, if two angles and the included side of one triangle are equal to two angles and the included side of another triangle. Then the congruency rule is:**

a) SSS

b) ASA

c) SAS

d) None of the above

**Answer**

(b)

**Q9. A triangle in which two sides are equal is called:**

a) Scalene triangle

b) Equilateral triangle

c) Isosceles triangle

d) None of the above

**Answer**

(c)

**Q10. The angles opposite to equal sides of a triangle are:**

a) Equal

b) Unequal

c) supplementary angles

d) Complementary angles

**Answer**

(a)

**Q11.** In two triangles DEF and PQR, if DE = QR, EF = PR and FD = PQ, then

a) ∆DEF ≅ ∆PQR

b) ∆FED ≅ ∆PRQ

c) ∆EDF ≅ ∆RPQ

d) ∆PQR ≅ ∆EFD

**Answer**

(b)

**Q12.** In ∆ABC, BC = AB and ∠B = 80°. Then ∠A is equal to:

a) 80^{o}

b) 40^{o}

c) 50^{o}

d) 100^{o}

**Answer**

(c)

**Q13.** Two sides of a triangle are of length 5 cm and 1.5 cm. The length of the third side of the triangle cannot be:

a) 3.6 cm

b) 4.1 cm

c) 3.8 cm

d) 6.9 cm

**Answer**

(d)

**Q14.** In ∆PQR, if ∠R > ∠Q, then

a) QR > PR

b) PQ > PR

c) PQ < PR

d) QR < PR

**Answer**

(b)

**Q15.** D is a point on the side BC of a ΔABC such that AD bisects ∠BAC. Then

a) BD : DC = AB : AC

b) CD > CA

c) BD > BA

d) BA > BD

**Answer**

(a)

**Q16.** It is given that Δ ABC ≅ Δ FDE and AB = 5 cm, ∠B = 40° and ∠A = 80°. Then which of the following is true?

a) DF = 5 cm, ∠F = 60°

b) DF = 5 cm, ∠E = 60°

c) DE = 5 cm, ∠E = 60°

d) DE = 5 cm, ∠D = 40°

**Answer**

(b)

**Q17.** All the medians of a triangle are equal in case of a:

a) Scalene triangle

b) Right angled triangle

c) Equilateral triangle

d) Isosceles triangle

**Answer**

(c)

**Q18.** In the given figure, PS is the median then ∠QPS?

a) 40^{o}

b) 50^{o}

c) 80^{o}

d) 90^{o}

**Answer**

(b)

**Q19.** In triangle PQR if ∠Q = 90°, then:

a) PQ is the longest side

b) QR is the longest side

c) PR is the longest side

d) None of these

**Answer**

(c)

**Q20.** In the given figure, AB = AC and ∠B = 50° then; ∠A is:

a) 50^{o}

b) 80^{o}

c) 100^{o}

d) 130^{o}

**Answer**

(b)

**Q21.** In the given figure, if the exterior angle is 135^{o} then ∠P is:

a) 45^{o}

b) 60^{o}

c) 80^{o}

d) 90^{o}

**Answer**

(d)

**Q22.** If in ΔPQR, PQ = PR then:

a) ∠P = ∠R

b) ∠P = ∠Q

c) ∠Q = ∠R

d) None of these

**Answer**

(c)

**Q23.** In a triangle ABC, ∠B = 35° and ∠C = 60°, then

a) ∠A = 80°

b) ∠A = 85°

c) ∠A = 120°

d) ∠A = 145°

**Answer**

(b)

**Q24.** In triangles ABC and PQR, AB = AC, ∠C = ∠P and ∠B = ∠Q. The two triangles are:

a) Isosceles but not congruent

b) Isosceles and congruent

c) Congruent but not isosceles

d) Neither congruent nor isosceles

**Answer**

(a)

**Q25.** In triangles ABC and DEF, AB = FD and ∠A = ∠D. The two triangles will be congruent by SAS axiom if:

a) BC = EF

b) AC = DE

c) AC = EF

d) BC = DE

**Answer**

(b)