CBSE Class 10 · Chapter 8 · Trigonometry · 2026-27
Introduction to Trigonometry Class 10: MCQ and case study questions
15 multiple-choice questions and 2 case-based questions on the current (rationalised) syllabus, in the style of the board paper's Sections A and E. Try each one first; the answer, a one-line reason and a worked solution open on a tap.
15 MCQs (1 mark each)
2 case studies (4 marks each)
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Multiple-choice questions
Choose one option. Section A of the board paper has 18 MCQs of 1 mark each, spread over all chapters.
Q1
·1 mark·Multiple choiceTrigonometric ratios
In \(\triangle ABC\), right-angled at \(B\), \(AB = 5\) cm and \(BC = 12\) cm. Then \(\sin A\) is
(a)\(\dfrac{5}{13}\)
(b)\(\dfrac{12}{13}\)
(c)\(\dfrac{12}{5}\)
(d)\(\dfrac{13}{12}\)
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Answer: (b) \(\dfrac{12}{13}\)
Why: sin A = opposite/hypotenuse = BC/AC, with AC = 13.
\(AC = \sqrt{25 + 144} = 13\) cm. \(\sin A = \dfrac{BC}{AC} = \dfrac{12}{13}\).
Q2
·1 mark·Multiple choiceTrigonometric ratios
If \(\tan A = \dfrac{8}{15}\), where \(A\) is acute, then \(\sec A\) equals
Section E of the board paper has three case-based questions of 4 marks: a real-life passage, then parts of 1, 1 and 2 marks, with a choice (OR) on the 2-mark part.
Case study 1: Solar panel frame (4 marks)
A solar panel on a flat roof rests on a frame shaped like a right triangle \(ABC\), right-angled at \(B\). The horizontal bar \(AB\) is \(12\) dm long and the vertical post \(BC\) is \(5\) dm tall. The panel lies along \(AC\), and \(\theta = \angle BAC\) is its angle of tilt.
A geometry box has two set squares. One is a right triangle with angles \(30^\circ\), \(60^\circ\) and \(90^\circ\), whose longest side (hypotenuse) is \(20\) cm. The other is a right isosceles triangle with angles \(45^\circ\), \(45^\circ\), \(90^\circ\), whose two equal sides are \(12\) cm each.
(i) Using \(\sin 30^\circ\), find the side of the first set square opposite the \(30^\circ\) angle. [1 mark]
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Answer: \(10\) cm
Opposite side \(= 20 \sin 30^\circ = 20 \times \dfrac12 = 10\) cm. A1
(ii) Using \(\cos 30^\circ\), find the third side of the first set square. [1 mark]
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Answer: \(10\sqrt3\) cm
Adjacent side \(= 20\cos 30^\circ = 20 \times \dfrac{\sqrt3}{2} = 10\sqrt3\) cm. A1
(iii) Show that \(\dfrac{2\tan 30^\circ}{1 + \tan^2 30^\circ} = \sin 60^\circ\). [2 marks]
This free set is separate from the chapter's question bank. On the Introduction to Trigonometry chapter page the revision notes and the first step of the Route to 95 are free for everyone. CBSE Essentials adds all 38 questions in the chapter bank (short and long answers, assertion–reason and more case studies) with their full step-marking schemes, the Route to 95 checkpoints with your progress saved, Skill Builders and the full common-mistakes library. There is no AI marking on CBSE Math Revision: you check your work against the marking scheme.
Original questions written by CBSE Math Revision for the CBSE 2026-27 syllabus; not taken from NCERT, NCERT Exemplar or CBSE papers. Every answer was re-checked by computer algebra and by an independent reviewer. CBSE Math Revision is independent and not affiliated with CBSE or NCERT. Spotted a slip? Tell us and it goes in the corrections log.