Support · Mathematics Standard 11–12 – Year 12 – Standard 2 · Trigonometry
Support Apply the cosine rule c² = a² + b² - 2abcosC in a given triangle ABC to find the value of an unknown side
Resources for the prerequisite content of this dot point: earlier-stage (or earlier sub-level) dot points in the same strand that students usually need first. Use these to fill gaps before or alongside the core lesson.
Prerequisite links are draft mappings generated from the syllabus structure (earlier stage, same strand, closest content). They are being reviewed by teachers. Spot a poor match? Tell us.
Prerequisite dot points
Apply the sine rule in a given triangle ABC to find the value of an unknown side
Stage 5 · Trigonometry C (Path) Draft mapping
- Interactive toolStarterMaths Is Fun: The law of sinesUse it for: Sine rule with examples.
- Corbettmaths practice questions: Trigonometry: sine rule (sides)Use it for: Free printable graded practice questions (with answers) on trigonometry: sine rule (sides) for drill or a quick check.
- VideoStarterCorbettmaths video: Trigonometry: sine rule (sides)Use it for: Short worked-example video on trigonometry: sine rule (sides) to model the method before practice or for flipped revision.
Apply the cosine rule to find the unknown sides for a given triangle ABC.
Stage 5 · Trigonometry C (Path) Draft mapping
- Interactive toolStarterMaths Is Fun: The law of cosinesUse it for: Cosine rule with examples.
- Corbettmaths practice questions: Trigonometry: sine rule (sides)Use it for: Free printable graded practice questions (with answers) on trigonometry: sine rule (sides) for drill or a quick check.
- VideoStarterCorbettmaths video: Trigonometry: cosine rule (sides)Use it for: Short worked-example video on trigonometry: cosine rule (sides) to model the method before practice or for flipped revision.
Use graphing applications to verify the cosine rule c² = a² + b² - 2abcosC.
Stage 5 · Trigonometry C (Path) Draft mapping
- Desmos Graphing CalculatorUse it for: Graph lines, parabolas and exponentials live; find intersections to solve simultaneous equations.
- Interactive toolEnrichmentGeoGebra ClassicUse it for: Dynamic geometry and graphing for constructions and proofs.
- Interactive toolStarterMathigon: Sine and cosine rulesUse it for: Explore where the sine and cosine rules come from, then apply them.