GCSE Edexcel Trigonometry - Edexcel Trigonometric graphs - Higher The three trigonometric ratios; sine, cosine and tangent are used to calculate angles and lengths in right-angled triangles. The ...

sin x ∘ = 0.5 x ∘ = sin 1 (0.5) x ∘ = 30 ∘ So we know that the first solution is 30 ∘ as previously predicted from the graph.