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) ...

👉 Learn how to evaluate the six trigonometric functions given a right triangle. A right triangle is a triangle with 90 degrees as one of its angles. A right triangle is made up of two legs, which ...

👉 Learn how to evaluate inverse trigonometric functions. When an angle is unknown but the value of one of the trigonometric functions of the angle is known, we can evaluate the value of the angle ...

The ancient Babylonians – who lived from about 4,000BCE in what is now Iraq – had a long forgotten understanding of right-angled triangles that was much simpler and more accurate than the conventional ...

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.