§ Задание 762\[\boxed{\mathbf{762}.\ }\]\[\textbf{а)}\ S = 4,5\ см^{2}.\]\[\textbf{б)}\ S = 5\ см^{2}.\]\[\textbf{в)}\ S = 11\ см^{2}.\]\[\textbf{г)}\ S = 12\ см^{2}.\]