HOME
Number Number Language Accuracy Calculations Fractions and Decimals Percentages Ratio and Proportion Indices & Standard Form Interest Venn Diagrams Algebra and Graphs Algebraic Indices Variation Functions Geometry Mensuration Measures Perimeter/Area/Volume Coordinate Geometry Trigonometry Pythagoras' Theorem Basic Trigonometry Trig Word Problems 3D Trigonometry Sine and Cosine Rule Area of any Triangle Bearings Angles of Elevation/Depression Vectors, Matrices and Transformations Probability Basic Probability Further Probability Statistics Mean/Mode/Median/Range Collecting and displaying data Cumulative Frequency Great LinksProbabilityVenn DiagramSequencesLoci 
What are the Sine and Cosine rule
So far we have been working with rightangled triangles. We discovered that Pythagoras' Theorem and Trigonometry allow us to calculate lengths in rightangled triangles. Trigonometry we also use when we want to calculate angles in rightangled triangles. But what do we do when we are not given a rightangled triangle? How do we calculate lengths and angles in nonrightangled triangles? In those cases we use the Sine and Cosine rule (which are actually still based upon the trigonometric ratios in rightangled triangles). Have a proper look at all of the following videos and make sure you know exactly how to approach this important IGCSE maths topic. Good luck and have fun!
Solving more Example Questions about the Sine Rule
Once you know what the Sine Rule is and how we can use it to calculate lengths and angles in all triangles, it is time to study the following maths example questions during your maths revision. The first video will prove the sine rule to you and show you it is not a magic formula! The next three videos will provide you with example questions in which the sine rule is used to calculate lengths and angles. Make sure to study all videos for every time something new will be added (something to take care of, a tip etc). So pass your IGCSE GCSE Maths exam and look at the following maths activities!
Cosine rule
The previous three videos explain step by step to you how to use the Cosine Rule to calculate angles and lengths in triangles. Hopefully you have studies all three maths activities during your maths revision. Do not think you know it all now and study the next two example questions about the Cosine Rule. Once you have studied those too you will understand everything about the Cosine Rule and pass your next IGCSE GCSE Maths exam.

Activity
The worksheet below I created for you to practice your understanding of the sine and cosine rule. If you want to be successful and pass your next maths exam, analyse for each question the situation properly and decide which strategy (sine or cosine rule) to use. I hope you can read the numbers properly because for some reason the quality decreased after uploading the document. Scroll all the way down for the answers (not too quickly of course because you first want to try it yourself!). Good luck and have fun!!
Your browser does not support viewing this document. Click here to download the document.
Past Exam Question involving Cosine Rule and moreCheck the next video during your maths revision. I will solve a past paper question which includes a question about the cosine rule. I will also explain how to use Trigonometry and Pythagoras' Theorem to calculate lengths and how to calculate the volume of prisms.


Past Paper Question about Bearings, Sine and Cosine ruleOne of you asked me to help with the following maths question. I will solve this past paper question for you and explain how to use the sine rule, how to use the cosine rule and how to calculate bearings. A great activity to practise during your maths revision!

