congruence of triangles for 7th class on the bases of academic standards
Answers
Congruence of triangles:
In this section,we will learn about how the concept of congruency relates specifically with triangles. What do we mean by congruent triangles? On the basis of the previous section,we can say that congruent figures have the same shape and size. Two triangles therefore will be congruent if the size and shape of the triangles are the same.
In simple words,two triangles are said to be congruent if and only if one triangle
can be made to superpose on the other to cover it completely.
Consider the two triangles,∆ABC and ∆XYZ (in the picture)
Are these two triangles congruent? If we place ∆ABC over ∆XYZ, in such a way that the vertex A is placed over the vertex Z,then ∆ABC will completely superpose ∆XYZ.
We can therefore say that ∆ABC is congruent to ∆XYZ.
However,if ∆ABC is placed over ∆XYZ in any order, that is vertex A is placed over vertex Y or Z and the other vertices are also placed accordingly, then the two triangles will not overlap. This does not mean that the two triangles are not congruent.
This,while comparing two congruent triangles, care has to be taken that we compare the 'corresponding' equal parts.
Two triangles are said to be congruent if equality exists between them due to which all six parts of them,three sides and three angles of each,have equal measures
problems( in the pics)
