Introduction to Trigonometry
Class 10 · Mathematics
3 ideas in Class 10 Mathematics, explained in plain words, with games and quizzes to practise.
Right-Triangle Trigonometric Ratios
Part of: Right-Triangle Trigonometric Ratios
Sine, cosine and tangent compare opposite, adjacent and hypotenuse sides for an acute angle. Cosecant, secant and cotangent are their reciprocals.
Why it matters. Trigonometric ratios connect angles with lengths and help solve indirect measurement problems.
Try it in two minutes
- Mark the angle and identify opposite, adjacent and hypotenuse.
- Choose the ratio that uses the needed sides.
- Use special values or an identity to find a missing ratio.
Try at home. Draw a right triangle and label the opposite and adjacent sides for each acute angle in turn.
Special Angles and Boundary Values
Part of: Special Angles and Boundary Values
The chapter gives exact ratios for 0°, 30°, 45°, 60° and 90°. Some ratios at boundary angles are undefined when their denominator is zero.
Why it matters. Trigonometric ratios connect angles with lengths and help solve indirect measurement problems.
Try it in two minutes
- Mark the angle and identify opposite, adjacent and hypotenuse.
- Choose the ratio that uses the needed sides.
- Use special values or an identity to find a missing ratio.
Try at home. Draw a right triangle and label the opposite and adjacent sides for each acute angle in turn.
Trigonometric Identities
Part of: Trigonometric Identities
The ratios satisfy identities derived from the Pythagorean theorem: sin²A + cos²A = 1, 1 + tan²A = sec²A, and 1 + cot²A = cosec²A on their defined ranges.
Why it matters. Trigonometric ratios connect angles with lengths and help solve indirect measurement problems.
Try it in two minutes
- Mark the angle and identify opposite, adjacent and hypotenuse.
- Choose the ratio that uses the needed sides.
- Use special values or an identity to find a missing ratio.
Try at home. Draw a right triangle and label the opposite and adjacent sides for each acute angle in turn.
What your child will practise
- Right-Triangle Trigonometric Ratios: Desert Puzzle (Clue Puzzle)
- Right-Triangle Trigonometric Ratios: Ocean Quick Fire (Quick Fire)
- Special Angles and Boundary Values: Jungle Quick Fire (Quick Fire)
- Special Angles and Boundary Values: Number Quest (Match It Up)
- Trigonometric Identities: Mission Control Quest (Collect the Answer)
- Quiz: Right-Triangle Trigonometric Ratios (8 questions)
- Quiz: Special Angles and Boundary Values (8 questions)
- Quiz: Trigonometric Identities (8 questions)