# NCERT Class 7 Mathematics Solutions: Chapter 7 –Congruence of Triangles Exercise 7.2 Part 3

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1. In .

In

A student says that by AAA congruence criterion. Is he justified? Why or why not?

Answer:

No, because the two triangles with equal corresponding angles need not be congruent.

In such a correspondence, one of them can be an enlarged copy of the other.

Therefore, AAA property does not prove the two triangles congruent.

2. In the figure, the two triangles are congruent. The corresponding parts are marked. We can write

Answer:

In the figure, given two triangles are congruent.

So, the corresponding parts are:

Also,

[By SAS congruence rule]

3. Complete the congruence statement:

Answer:

In, , given triangles are congruent so the corresponding parts are:

, ,

So,

[By SSS congruence rule]

In , given triangles are congruent so the corresponding parts are:

, ,

So,

[By SSS congruence rule]