A parallelogram ABCD ABCD\,ABCD has area k cm2k \text{ cm}^2k cm2, where 0<k<600<k<600<k<60. Given AB AB\,AB has length 5 cm, BC BC\,BC has length 12 cm and angle ABC ABC\,ABC is obtuse.
Find the size of angle ABC ABC\,ABC in terms of kkk.
Find the length of the diagonal AC AC\,AC in terms of kkk.
217 exam-style questions on Edexcel A Level Maths Trigonometric Ratios, covering 9.1 The Cosine Rule, 9.2 The Sine Rule, 9.3 Areas of Triangles, 9.4 Solving Triangle Problems, 9.5 Graphs of Sine, Cosine and Tangent, and 9.6 Transforming Trigonometric Graphs. Each one has a worked solution and a mark scheme showing where the marks go.