"a rectangular foundation with dimensions a and $2$a supports a circular concrete column with a radius of $12$ in$.$ the column carries a load of $160$ kips and the foundation is embedded $3\mathrm{.}5$ ft below grade. The thickness of the footing is $1\mathrm{.}5$ ft$,$ and it is constructed on soil with an allowable bearing capacity of $8$ k$/$ft$^2."$

concrete unit weight $=145$ lb$/$ft$^3$

soil unit weight $=85$ lb$/$ft$^3$

a$)$ design the required surface area fir the foundation $($consider only given load$)$

b$)$ analyse your design $($consider weight of the foundation, column and soil above the foundation$)$