Free Congruence of Triangles 02 Practice Test - 7th grade 

Question 1

Consider the figure below:

The triangles ABC and PQR are similar.

A.

True

B.

False

SOLUTION

Solution : A

In the given figure:

In  ΔABC and ΔPQR

AB = PR

BC = PQ

AC = QR

Therefore, ΔABCΔRPQ by SSS criterion.

Since all congruent triangles are similar triangles. ΔABC and ΔRPQ  are also similar.

Question 2

Consider the figure below:

The two triangles are congruent by SAS criterion only.

A.

True

B.

False

SOLUTION

Solution : B

In the given figure:

In  ΔABC and ΔPQR

AB = PR

BC = PQ

AC = QR

Therefore, ΔABCΔPQR by SSS criterion.
Hence, the statement is false.

Question 3

Consider the figure below:

If AB = 5 cm; QR = 7cm; then find the value of AC (in cm.), if the perimeter of ABC is 18cm.


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SOLUTION

Solution :

In the given figure:

In  ΔABC and ΔPQR

AB = PR = 5 cm

BC = PQ

AC = QR = 7 cm

Therefore, ΔABCΔPQR by SSS criterion.

Since perimeter = 18cm

 AB + AC + BC = 18 cm,

BC = 18 - 5 - 7 = 6 cm.

Therefore, 
AB = PR = 5 cm

BC = PQ = 6 cm

AC = QR = 7 cm 
So, the answer is 7 cm.

Question 4

Consider the figure below.

 

If A=50,  and Q=60, then find the value of B (in degrees).


___

SOLUTION

Solution :

In the given figure:

In  ΔABC and ΔPQR

AB = PR (Given)

BC = PQ (Given)

AC = QR (Given)

Therefore, ΔABCΔPQR by SSS condition.

Therefore,

A=R=50;

B=P;

C=Q=60.

Using angle sum property in  Δ ABC,
A+B+C=180
  50+B+60=180
 B=70

Question 5

In the below quadrilateral ABCD, if AD = BC and DAB = CBA, then what is the relation between ABD and BAC ?

A.

ABD = BAC

B.

ABDBAC

C.

ABD > BAC

D.

DABBAC

SOLUTION

Solution : A

In ΔABD and ΔBAC,
AD = BC  (Given)
BAD = CBA (Given)
AB = BA  (Side common to both triangles)
Hence ΔABDΔBAC
(by SAS congruence condition). 
Thus, ABD = BAC
(congruent parts of congruent triangles). 

 

Question 6

If ΔDEFΔBCA , then the angle of ΔBCA  that corresponds to E  is _______ and side FD corresponds to side ________.

A.

A, BC

B.

B, AB

C.

C, AB

D.

Both C​ and A​, BC

SOLUTION

Solution : C

We know that if two triangles are congruent, then their corresponding parts are equal.

Since ΔDEFΔBCA, therefore E=C and FD=AB.

Question 7

In ΔABC and ΔPQR , AB = 4 cm, BC = 5 cm, AC = 6 cm and PQ = 4 cm, QR = 5 cm, PR = 6 cm, then which of the following is true?

A.

ΔABCΔRQP

B.

ΔABCΔQRP

C.

ΔABCΔPQR

D.

ΔBACΔPQR

SOLUTION

Solution : C

In ΔABC and ΔPQR

AB = PQ = 4cm ,  (Given)

BC = QR = 5 cm,  (Given) 

AC = PR = 6 cm;  (Given)

Hence, ΔABCΔPQR  (By SSS criterion).

Question 8

If ΔABCΔPQR, then AB is equal to ___.

 

A.

PR

B.

QR

C.

PQ

D.

Both PR and QR

SOLUTION

Solution : C

Since  ΔABCΔPQR,
corresponding sides of congruent triangles will be equal.
Hence, AB = PQ.

Question 9

All the following are criteria for measuring the congruency of triangles except the _____.

A.

SAS 

B.

SSS

C.

ASA 

D.

AAA 

SOLUTION

Solution : D

The criteria for congruence of triangles are SSS criterion, SAS criterion, ASA criterion and RHS criterion.

AAA is not a criterion for congruence as it does not ensure the equality of sides of the two triangles.

Note: AAA is a criterion for 'Similarity' of triangles.

Question 10

Two triangles are congruent if they have

A.

Same name

B.

Equal measures

C.

Same shape

D.

Same direction

SOLUTION

Solution : B and C

Two triangles(or any geometric figures) are congruent if they have same shape and equal measures (i.e., all corresponding sides and angles are equal). This is because two triangles are said to be congruent only if they coincide when superimposed which is possible only if all their corresponding angles and sides are equal.