# The Area Rule

> This section finds the area of any triangle from two sides and the included angle: 1/2absin C, and the two cyclic twins. Drop a perpendicular to derive it. When the included angle is obtuse, sin is…

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## Full notes

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## More in Trigonometry: Sine, Cosine and Area Rules

- [Right-angled Triangles](https://www.hlayiso.com/grade-12/mathematics/notes/trigonometry-sine-cosine-and-area-rules/right-angled-triangles) — Previous section
- [The Sine Rule](https://www.hlayiso.com/grade-12/mathematics/notes/trigonometry-sine-cosine-and-area-rules/the-sine-rule) — Next section
- [All Trigonometry: Sine, Cosine and Area Rules sections](https://www.hlayiso.com/grade-12/mathematics/notes/trigonometry-sine-cosine-and-area-rules)

## Frequently asked questions

### What will I learn in "The Area Rule"?

This section covers The Area Rule as part of Trigonometry: Sine, Cosine and Area Rules in Grade 12 Mathematics. You'll find clear explanations, worked examples, and key definitions aligned to the CAPS curriculum.

### Is this section aligned with the CAPS curriculum?

Yes. All notes on Hlayiso, including "The Area Rule", are written against the official CAPS curriculum and ATP for Grade 12 Mathematics.

### What should I study after "The Area Rule"?

Continue with the next section in Trigonometry: Sine, Cosine and Area Rules, or test your understanding with the interactive quiz linked to this section.

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