72. (a) Find the magnitude and direction of the vector $\overrightarrow{\boldsymbol{R}}$ that is the sum of the three vectors $\overrightarrow{\boldsymbol{A}}, \overrightarrow{\boldsymbol{B}}$, and $\overrightarrow{\boldsymbol{C}}$ in Fig.1.34. In a diagram, show how $\overrightarrow{\boldsymbol{R}}$ is formed from these three vectors.

72. (a) Find the magnitude and direction of the vector $\overrightarrow{\boldsymbol{R}}$ that is the sum of the three vectors $\overrightarrow{\boldsymbol{A}}, \overrightarrow{\boldsymbol{B}}$, and $\overrightarrow{\boldsymbol{C}}$ in Fig.1.34. In a diagram, show how $\overrightarrow{\boldsymbol{R}}$ is formed from these three vectors. (b) Find the magnitude and direction of the vector $\vec{S}=\overrightarrow{\boldsymbol{C}}-\overrightarrow{\boldsymbol{A}}-\overrightarrow{\boldsymbol{B}} \cdot$ In a diagram, show how $\overrightarrow{\boldsymbol{S}}$ is formed from these three vectors.