A triangle with vertices AAA, BBB, and C C\,C is shown. Side AB AB\,AB has a length of 5 m, and side AC AC\,AC has a length of 7 m. The angle at vertex A A\,A is 42∘42^\circ42∘.
Work out the length of BCBCBC.
Give your answer to 3 significant figures.
The Cosine Rule Questions
Practise OCR GCSE Maths The Cosine Rule with exam-style questions for Foundation and Higher tier. 44 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.