Mathematics Exercise for Sine and Cosine Rules

The article below is discussing sine and cosine rules. This is for exercise GCSE Edexcel Curriculum

Sine Rule

The Sine Rule can be used in any triangle (not just right-angled triangles) where aside and its opposite angle are known.

Finding Sides

If you need to find the length of a side, you need to use the version of the Sine Rule where the lengths are on the top:       a = b sin(A) sin(B) You will only ever need two parts of the Sine Rule formula, not all three. In this case, you will need to know at least one pair of a side with its opposite angle to use the Sine Rule. Cosine Rule The Cosine Rule can be used in any triangle where you are trying to relate all three sides to one angle. Finding Sides If you need to find the length of a side, you need to know the other two sides and the opposite angle. You need to use the version of the Cosine Rule where a2 is the subject of the formula:      a2 = b2 + c2 – 2bc cos(A) Side a is the one you are trying to find. Sides b and c are the other two sides, and angle A is the angle opposite side a.

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Question Number 1. 

Calculate The length of the Lighthouse?

Question Number 2.

Which Port should Dickho choose? Explain your Answer

Note:  Please leave the comments for discussion

See Also: 

• Properties of Circle
• All About the Whole Number
• Introduction of Algebra