Answer
$Area=0.221$
Work Step by Step
$s=\frac{a+b+c}{2}=\frac{\frac{4}{5}+\frac{3}{4}+\frac{5}{8}}{2}=\frac{87}{80}$
$Area=\sqrt {s(s-a)(s-b)(s-c)}=\sqrt {\frac{87}{80}(\frac{87}{80}-\frac{4}{5})(\frac{87}{80}-\frac{3}{4})(\frac{87}{80}-\frac{5}{8})}=0.221$
