# 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

similarbecause they have radius in fixed proportion.

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

**Solution:**

All squares are

similarbecause the ratio of corresponding sides are equal.

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

**Solution:**

All

Equilateraltriangles 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

equaland (b) their corresponding sides areproportional.

### Question 2. Give two different examples of pair of

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

**Solution:**

(i) Similar figures.

- All rectangular boards are similar
- All circular rings are similar

(ii) Non-similar figures

- A notebook and a pen are non-similar
- 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.