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The measurements of Δ LMN and Δ… (Class 10 Maths 2025, Q11)

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MathsCBSE Class 10 · Standard · Board exam 2025, set 30/3/1 · 1 mark · MCQ

CBSE Class 10 Mathematics Standard 2025: question 11

Set in the CBSE Class 10 board exam of 2025, paper 30/3/1, section A, question 11, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q11 · 1 mark · MCQTriangles

The measurements of LMN and ABC are shown in the figure given below. The length of side AC is :

  1. (A)16 cm
  2. (B)7 cm
  3. (C)8 cm
  4. (D)4 cm

Figure in the paper: Triangle LMN: LM = 45 cm, LN = 72 cm, MN = 63 cm, angle at M = , angle at N = . Triangle ABC: AB = 5 cm, angle at A = , angle at B = , with side AC to be found and BC the base. See it in the official paper.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 30/3/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Find the third angle of triangle LMN.

Hint 2

Use ratio of corresponding sides AB/LM.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. In , . So , : (AA).

    ½ mark

  2. cm. Option (C).

    ½ mark

Answer: 8 cm, option (C)

Where the marks are

  • Establishes similarity by AA (½ mark)
  • AC = 8 cm (½ mark)

Revise the chapter

  • Chapter: Triangles (notes, formulas, where marks are lost and every past question)
Practise this chapterBoard-style questions from Triangles, one at a time, marked against the answer key and marking points.Back to the full paper2025 board paper, set 30/3/1 (Standard): every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.