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Class 9 Maths MCQ Questions of Triangles with Answers?

Answer 1

We are providing Class 9 Maths MCQ Questions of Triangles that covers topics of triangles orthocenter, circumcenter of the triangle, and center of the triangle etc. Students can practice objective types questions to score good marks in the upcoming exam. MCQ Questions are provided here with answers. 

Students can tackle Class 9 Maths MCQ Questions with Answers to access their preparation level. Let's start practice of given MCQ Questions bleow: -

Practice MCQ Questions for Class 9 Maths

1. If △ABC≅△PQR, then which of the following is not true?

(a) BC=PQ
(b) AC=PR
(c) QR=BC
(d) AB=PQ

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

(a) 70°
(b) 110°
(c) 55°
(d) 130°

3. 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

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

(a) 80°

(b) 40°

(c) 50°

(d) 100°

5. 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

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

(a) Scalene triangle
(b) Equilateral triangle
(c) Isosceles triangle
(d) None of the above

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

(a) Equal
(b) Unequal
(c) supplementary angles
(d) Complementary angles

8. 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

9. 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

10. 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

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

(a) 90°
(B)180°
(c) 120°
(d) 60°

12. 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

13. In a right triangle, the longest side is:

(a) Perpendicular
(b) Hypotenuse
(c) Base
(d) None of the above

14. In ∆PQR, if ∠R > ∠Q, then

(a) QR > PR
(b) PQ > PR
(c) PQ < PR
(d) QR < PR

15. 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

16. 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

17. Which of the following is not a criterion for congruence of triangles?

(a) SAS
(b) ASA
(c) SSA
(d) SSS

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

(a) Isosceles and congruent
(b) Isosceles but not congruent
(c) Congruent but not isosceles
(d) Neither congruent nor isosceles

19. In ∆ PQR, ∠R = ∠P and QR = 4 cm and PR = 5 cm. Then the length of PQ is

(a) 2 cm
(b) 2.5 cm
(c) 4 cm
(d) 5 cm

20. If AB = QR, BC = PR and CA = PQ, then

(a) ∆ PQR ≅ ∆ BCA
(b) ∆ BAC ≅ ∆ RPQ
(c) ∆ CBA ≅ ∆ PRQ
(d) ∆ ABC ≅ ∆ PQR

21. 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

22. Two sides of a triangle are of lengths 5 cm and 1.5 cm. The length of the third side of the triangle cannot be

(a) 3.4 cm
(b) 3.6 cm
(c) 3.8 cm
(d) 4.1 cm

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Answer 2

1. Answer: (a) BC=PQ

Explanation: Given, ABC≅PQR
Thus, corresponding sides are equal.
Hence, AB=PQ 
AC=PR
BC=QR
Hence, BC=PQ is not true for the triangles.

2. Answer: (c) 55°

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°

3. Answer: (b) ∆FED ≅ ∆PRQ

4. Answer: (c) 50°

5. Answer: (b) ASA

6. Answer: (c) Isosceles triangle

7. Answer: (a) Equal

8. Answer: (d) BF = CE

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)

9. Answer: (c) BE=CF

Explanation: ∠A = ∠A (common arm)

∠AEB = ∠AFC (Right angles)

AB = AC (Given)

∴ ΔAEB ≅ ΔAFC

Hence, BE = CF (by CPCT)

10. Answer: (a) ∠ABD = ∠ACD

Explanation: AD = AD (Common arm)

AB = AC (Sides of isosceles triangle)

BD = CD (Sides of isosceles triangle)

So, ΔABD ≅ ΔACD.

∴ ∠ABD = ∠ACD (By CPCT)

11. Answer: (d) 60°

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°

12. Answer: (c) BD<CD

Explanation: In ΔABD and ΔACD,

∠ADB = ∠ADC = 90°

AB = AC (Given)

AD = AD (Common)

∴ ΔABD ≅ ΔACD (By RHS congruence condition)

BD = CD (By CPCT)

13. Answer: (b) Hypotenuse

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.

14. Answer: (b) PQ > PR

15. Answer: (a) BD : DC = AB : AC

16. Answer: (c) Equilateral triangle

17. Answer: (c) SSA

Explanation: SSA is not a criterion for the congruence of triangles. Whereas SAS, ASA and SSS are the criteria for the congruence of triangles. 

18. Answer: (b) Isosceles but not congruent

Explanation: Consider two triangles, ABC and PQR. If the sides AB = AC and ∠C = ∠P and ∠B = ∠Q, then the two triangles are said to be isosceles, but they are not congruent.

19. Answer: (c) 4 cm

Explanation: Given that, in a triangle PQR, ∠R = ∠P.

Since, ∠R = ∠P, the sides opposite to the equal angles are also equal.

Hence, the length of PQ is 4 cm.

20. Answer: (c) ∆ CBA ≅ ∆ PRQ

Explanation: Consider two triangles ABC and PQR.

Given that, AB = QR, BC = PR and CA = PQ.

By using Side-Side-Side (SSS rule),

We can say, ∆ CBA ≅ ∆ PRQ.

21. Answer: (c) PR is the longest side

22. Answer: (a) 3.4 cm

Explanation: If two sides of a triangle are of lengths 5 cm and 1.5 cm, then the length of the third side of the triangle cannot be 3.4 cm. Because the difference between the two sides of a triangle should be less than the third side.