**Use similarity to investigate the constancy of the sine, cosine and tangent ratios for a given angle in right-angled triangles (ACMMG223)**

**Apply trigonometry to solve right-angled triangle problems (ACMMG224)**

**LO:To investigate Sine, Cosine and Tangent ratios and use trigonometry to solve right-angled triangle problems.
**

**Know:**

- the properties of right-angled triangles.

**Understand:**

- That there is a link between the sine, cosine and tangent ratios in right-angled triangles

**Do:**

- I can use the sine, cosine and tangent ratios.

**Properties of Right-Angled Triangles**

**Properties of Right-Angled Triangles**

### “Opposite” is the **opposite **to the angle.

“Adjacent” is **next to** the angle.

“Hypotenuse” is the **long side** of the right-angled triangle and is always **opposite** of the right angle.

### There are 3 ratios to help identify the length of the sides.

### sin angle = opposite side / hypotenuse

### cos angle = adjacent side / hypotenuse

### tan angle = opposite side / adjacent side

**Teaching Ideas**

**Teaching Ideas**

**Trigonometry Videos**

**Trigonometry Videos**