Class 10 NCERT Solutions- Chapter 6 Triangles – Exercise 6.1

Question 1. Fill in the blanks by using the correct word given in brackets.

(i) All circles are ……………. . (congruent/similar)

Solution:

All circles are similar because they have radius in fixed proportion.

(ii) All squares are …………… . (similar/congruent)

Solution:

All squares are similar because the ratio of corresponding sides are equal.

(iii) All …………….. triangles are similar. (isosceles/equilateral)

Solution:

All Equilateral triangles are similar because the ratio of corresponding sides are equal. 

(iv) Two polygons of the same number of sides are similar, if (a) their corresponding angles are …………… and (b) their corresponding sides are …………… (equal/proportional)

Solution:

Two polygons of the same number of sides are similar, if (a) their corresponding angles are equal and (b) their corresponding sides are proportional.

Question 2. Give two different examples of pair of

(i) similar figures. (ii) non-similar figures.

Solution:

(i) Similar figures. 

1. All rectangular boards are similar
2. All circular rings are similar

(ii) Non-similar figures

1. A notebook and a pen are non-similar
2. A rectangle and a circle are non-similar.

Question 3. State whether the following quadrilaterals are similar or not:

Solution:

Both the figures are non-similar. For similarity, the corresponding angles should be equal and corresponding sides are in the same ratio. But in this figure ratio of corresponding sides (AB/PQ = AS/PS = DC/SR = CB/RQ = 3/1.5 = 2) but corresponding angles are not equal.