Question

while checking the congruence of two figures which of the following is not allowed for superimposition of figures a translation b stretching c reflection d rotation​

Answer 1

Answer:

You can use the method of superposition. Take a trace-copy of one of them and place it over the other. If the figures cover each other completely, they are congruent. Alternatively, you may cut out one of them and place it over the other. Beware! You are not allowed to bend, twist or stretch the figure that is cut out (or traced out). In Fig 7.3, if figure F1 is congruent to figure F2 , we write F1 ≅ F2.

Congruence among line segments

When are two line segments congruent? Observe the two pairs of line segments given here (Fig 7.4).

Answer 2

While checking the congruence of two figures, stretching is not allowed for superimposition.

• Congruent figures are the exact copies of each other.
• While rotating, translating (moving from one position to another), and reflecting (forming a mirror image) the dimensions or other characteristics of the figure remain the same. Thus the figures remain congruent.
• During stretching, the dimensions and the angles of the figure change. Hence, changing the congruency.