Trigonometry sin^2(A) + cos^2(A) = 1 SOH: sin= opposite/hypotenuse CAH: cosine= adjacent/hypotenuse TOA: tangent= opposite/adjacent sin(x)= cos(90-x) Ratio for 30:60:90 triangles: 1:√3:2 Ratio for 45:45:90 triangles: √2:√2:1