NCERT Solutions: Triangles (Exercise 6.1) - Notes | Study Mathematics (Maths) Class 10 - Class 10

Exercise 6.1

Q1. Fill in the blanks using the correct word given in brackets.
(i) All circles are _______(congruent, similar).
(ii) All squares are _______ (similar, congruent).
(iii) All _______ triangles are similar. (isosceles, equilateral).
(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).
Ans: (i) All circles are similar.
(ii) All squares are similar.
(iii) All equilateral triangles are similar.
(iv) Two polygons of the same number of sides are similar if:
(a) Their corresponding angles are equal and
(b) Their corresponding sides are proportional.

Q2. Give two different examples of pair of:
(i) similar figures 
(ii) non-similar figures.
Ans: 
(i).
(a) Any two circles are similar figures.
(b) Any two squares are similar figures.
(ii).
(a) A circle and a triangle are non-similar figures.
(b) An isosceles triangle and a scalene triangle are non-similar figures.

Q3. State whether the following quadrilaterals are similar or not.

Ans: No, the sides of quadrilateral PQRS and ABCD are proportional but their corresponding angles are not equal.
∴ These are not similar.