What is the cosine rule?

What is it?The cosine rule is a tool to find the size of an angle or the length of a side in a triangle.When to use it?- When we are given 2 sides and an angle- When we are given 3 sidesHow?For a triangle with sides a,b and c and angles A, B and C the cosine rule can be written as:a2 = b2 + c2 - 2bc cos Aorb2 = a2 + c2 - 2ac cos Borc2 = a2 + b2 - 2ab cos C

NG
Answered by Naomi G. Maths tutor

4683 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

At a football game number of men : number of women : number of children = 13 : 5 : 7 There are 4152 more men than women. Work out the number of children at the game.


Represent x = 0.0154 recurring as a fraction.


Factorise (5x^2 + 7x + 2)


Solve the simultaneous equations 3x + y = 11 and 2x + y = 8.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences