$3\mathrm{.}72$ a$.$ Determine the gage pressure at point $A$ in Fig. P$3,72.$

b$.$ If the barometric pressure is $737mm$ of mercury. express the pressure at point $A$ in kPa$(\frac{?}{abs}).$

FIGURE P$3\mathrm{.}72$ Manometer for Problem $3\mathrm{.}72.$