A surveyor's map shows a triangular region divided into two by a North-South boundary line of length y y\,y km. The line y y\,y is perpendicular to the base line of the region. The Western side of the region is bounded by paths of length 7 km and 11 km meeting at an angle of 65∘ 65^\circ\,65∘ at the Northwest vertex. The distance along the base line from the boundary y y\,y to the Eastern vertex is 4 km. The angle at the Eastern vertex is x∘x^\circx∘.
Work out the value of xxx.
Give your answer to 1 decimal place.
Practise Eduqas GCSE Maths The Cosine Rule with exam-style questions for Foundation and Higher tier. 44 questions, matched to the Eduqas GCSE Maths (C300QS) specification and written in Component 1 and Component 2 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.