NCERT Mathematics · Class 10 · English · 2026-27

Triangles — Exercise 6.1

Independently written, step-by-step solutions. Prompts below are concise paraphrases; use the official textbook for the complete question wording.

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Question 1

Complete the four similarity statements.

Step-by-step solution

Changing a circle’s radius, a square’s side, or an equilateral triangle’s side changes its scale but not its shape. Similar polygons must satisfy both the angle and side-ratio conditions.

Answer: (i) Similar; (ii) similar; (iii) equilateral; (iv)(a) equal, (b) proportional.

Resource ID: CB-10-M-CH6-EX6.1-Q1

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Question 2

Give two pairs of similar figures and two pairs of non-similar figures.

Step-by-step solution

Similar examples: two circles of radii 2 cm and 5 cm; two squares of sides 3 cm and 7 cm. Non-similar examples: a circle and a square; a 2×4 rectangle and a 2×5 rectangle (side ratios 1:2 and 2:5 differ).

Answer: Examples and reasons are listed above.

Resource ID: CB-10-M-CH6-EX6.1-Q2

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Question 3

Are the rhombus and square in Fig. 6.8 similar?

Step-by-step solution

The rhombus has side 1.5 cm and the square side 3 cm, so their sides are proportional with factor 1/2. However the square’s angles are all 90°, while the depicted rhombus has acute and obtuse angles. Both similarity conditions are required.

Answer: No; corresponding angles are unequal.

Resource ID: CB-10-M-CH6-EX6.1-Q3

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