2023-02-03 functio α:β:γ:δ AB:BΓ:ΓΔ:ΔΑ=√γ2+β2−2γβcosθ:√β2+δ2+2βδcosθ:√α2+δ2−2αδcosθ:√α2+γ2+2αγcosθ T.theodor 2023.2.3.