\(A=A_{\text{def}}=\frac{1}{2}\ {L_{p}}^{2}\left(\frac{\alpha_{0}-\sin{(\alpha}_{0})cos(\alpha_{0})}{{\alpha_{0}}^{2}}\right)\) (2)
\(l_{p}\left(\alpha\right)=\ \sqrt{\frac{2A\alpha^{2}}{\alpha-\sin(\alpha)cos(\alpha)}}\) (3)
\(l_{e}\left(\alpha\right)=L_{p}-l_{p}(\alpha)\ \) (4)