CBSE Class 10 Mathematics Standard 2024: question 6
Set in the CBSE Class 10 board exam of 2024, paper 30/2/1, section A, question 6, for 1 mark. Try it first; the hints and our step-by-step solution are below.
Q6 · 1 mark · MCQTriangles
In the given figure is shown. is parallel to . If cm, cm and cm, then is equal to
- (A) cm
- (B) cm
- (C) cm
- (D) cm
Figure in the paper: Triangle ABC with vertex A at the top, B bottom-left, C bottom-right. D lies on side AB and E lies on side AC, with segment DE drawn parallel to base BC. Labels: AD = 5 cm (along AD), DB = 2.5 cm (along DB), BC = 12 cm along the base. See it in the official paper.
Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 30/2/1.
Hints
Open one hint at a time and try again before the next.
Hint 1
The small and big triangles are similar.
Hint 2
AB = AD + DB = 7.5 cm.
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.
⇒ (AA), so .
- 1 mark
cm. Option (C).
Answer: 8 cm, option (C)
Where the marks are
- Uses similarity ratio AD/AB to get DE = 8 cm (1 mark)
Revise the chapter
- Chapter: Triangles (notes, formulas, where marks are lost and every past question)
- Topic: Basic Proportionality Theorem (Thales Theorem)
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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.