\[\boxed{\mathbf{740.ОК\ ГДЗ - домашка\ на}\ 5}\]
\[\textbf{а)}\ \overrightarrow{\text{AB}},\overrightarrow{\text{CD}}\ и\ \overrightarrow{\text{EF}} - коллинеарны;\ \]
\[\left| \overrightarrow{\text{AB}} \right| = 1\ см;\ \left| \overrightarrow{\text{CD}} \right| = 2,5\ см;\ \]
\[\left| \overrightarrow{\text{EF}} \right| = 4,5\ см;\]
\[\textbf{б)}\ \overrightarrow{\text{AB}}\ и\ \overrightarrow{\text{EF}} - коллинеарны,\ \]
\[\overrightarrow{\text{AB}}\ и\ \overrightarrow{\text{CD}} - не\ коллинеарны;\ \]
\[\left| \overrightarrow{\text{AB}} \right| = 1\ см;\left| \overrightarrow{\text{CD}} \right| = 2,5\ см;\]
\[\left| \overrightarrow{\text{EF}} \right| = 4,5\ см;\]