Trigonometrical Ratios
ICSE · Class 9 · Mathematics
Summary of Trigonometrical Ratios for ICSE Class 9 Mathematics. Key concepts, important points, and chapter overview.
Interactive on Super Tutor
Studying Trigonometrical Ratios? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for chapter summary and more.
1,000+ Class 9 students started this chapter today
Super Tutor has 5+ illustrations like this for Trigonometrical Ratios alone — flashcards, concept maps, and step-by-step visuals.
See them allOverview
Trigonometry is the branch of mathematics that deals with the measurement of triangles. The word 'Trigonometry' comes from Greek words meaning 'measurement of triangles'. In this chapter, we focus on right-angled triangles and learn about six important ratios called trigonometrical ratios. These rat
Key Concepts
In a right
In a right-angled triangle, for any acute angle (angle of reference): the side opposite to the acute angle is called the perpendicular, the side adjac
For any acute angle A
For any acute angle A in a right triangle: sin A = perpendicular/hypotenuse, cos A = base/hypotenuse, tan A = perpendicular/base, cot A = base/perpend
Trigonometrical ratios come in reciprocal pairs
Trigonometrical ratios come in reciprocal pairs: sin A and cosec A are reciprocals (sin A = 1/cosec A), cos A and sec A are reciprocals (cos A = 1/sec
When one trigonometrical ratio is given
When one trigonometrical ratio is given, we can find all others using the Pythagorean theorem (a² + b² = c²). If we know one ratio, we can determine t
Learning Objectives
- Understand the concept of perpendicular, base, and hypotenuse in a right triangle
- Learn the six trigonometrical ratios: sine, cosine, tangent, cotangent, secant, and cosecant
- Calculate trigonometrical ratios from given triangle measurements
- Apply reciprocal relationships between trigonometrical ratios
- Solve practical problems using trigonometrical ratios
Frequently Asked Questions
What are the important topics in Trigonometrical Ratios for ICSE Class 9 Mathematics?
How to score full marks in Trigonometrical Ratios — ICSE Class 9 Mathematics?
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Trigonometrical Ratios
Important Questions
Practice with board exam-style questions
Syllabus
What topics to cover
Revision Notes
Key points for last-minute revision
Study Plan
Step-by-step plan to ace this chapter
Flashcards
Quick-fire cards for active recall
Formula Sheet
All formulas in one place
Practice Quiz
Test yourself with a quick quiz
Concept Maps
See how topics connect visually
For serious students
Get the full Trigonometrical Ratios chapter — for free.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for ICSE Class 9 Mathematics.