3.2. Basic trigonometry
Before each question make sure calculator is in correct setting: degrees or radians?
Right-angle triangle (triangle with 90° angle)
Non-right angle triangles
Use this rule when you know: 2 angles and a side (not between the angles) or 2 sides and an angle (not between the sides).
Cosine rule: c2 = a2 + b2 − 2ab cosC
Use this rule when you know: 3 sides or 2 sides and the angle between them.
Area of a triangle: Area = ½ ab sinC
Use this rule when you know: 3 sides or 2 sides and the angle between them.
Three-figure bearings
Direction given as an angle of a full circle. North is 000° and the angle is expressed in the clockwise direction from North. So East is 090°, South is 180° and West 270°.
3.3. Circular functions
Trigonometric function y = a sin(bx + c) + d
Trigonometric identities
