👉 Learn how to find the reference angle of a given angle. The reference angle is the acute angle formed by the terminal side ...

👉 Learn how to evaluate trigonometric functions using the special right triangles. A right triangle is a triangle with 90 ...

a missing side in a right-angled triangle when another side and an angle are known. a missing angle in a right-angled triangle when two sides are known. In these formulae, the Greek letter θ (theta) ...

Being able to identify which formula to use, sine or cosine, and when, is necessary to answer questions on this topic successfully. Check you are confident in how to use the sine and cosine rules.