In triangle DEFDEFDEF, ED=6cmED = 6\text{cm}ED=6cm and DF=8cmDF = 8\text{cm}DF=8cm. Given that sin(∠DEF)=35\displaystyle \sin(\angle DEF) = \frac{3}{5}sin(∠DEF)=53 and ∠DEF \angle DEF\,∠DEF is acute.
Find ∠EFD\angle EFD∠EFD.
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.