Key learning points

1. The trigonometric ratios for 45° can be calculated using a square
2. The square should have lengths of 1 unit
3. By splitting the square into two right-angled triangles, you can calculate the ratio
4. The ratios for 0° and 90° can be reasoned

Keywords

• Trigonometric functions - Trigonometric functions are commonly defined as ratios of two sides of a right-angled triangle for a given angle.

• Sine function - The sine of an angle (sin(θ°)) is the y-coordinate of point P on the triangle formed inside the unit circle.

• Cosine function - The cosine of an angle (cos(θ°)) is the x-coordinate of point P on the triangle formed inside the unit circle.

• Tangent function - The tangent of an angle (tan(θ°)) is the y-coordinate of point Q on the triangle which extends from the unit circle.

Common misconception