Mathematik
> Rechtwinkliges Dreieck

Abbildung:
A, B, C = Ecken, a, b = Katheten, c = Hypotenuse, p, q = Hypotenusenabschnitte, p+q = c; α, β = Winkel; γ = 90°; a²+b² = c² (Satz des Pythagoras); a² = cp, b² = cq (Kathetensatz); h² = pq (Höhensatz); sin(α) = a/c, cos(α) = b/c, tan(α) = a/b; sin(β) = b/c, cos(β) = a/c, tan(β) = b/a; A = ab/2; U = a+b+c.