To determine how much of the wall is blue we first need to find its area. The wall is a rectangle, then its area is the product of its height and length:
[tex]\begin{gathered} A=(8\frac{2}{5})(16\frac{2}{3}) \\ A=(\frac{42}{5})(\frac{50}{3}) \\ A=(14)(10) \\ A=140 \end{gathered}[/tex]Hence, the area of the wall is 140 square ft. To determine how much of the wall is already painted we multiply this by 1/2, then:
[tex](140)(\frac{1}{2})=70[/tex]Therefore, 70 square ft are blue.