It's the sum of areas of:
two identical trapezoids [tex]A_1=\frac{a+b}2\cdot h[/tex]
a=6+8=14 in.
b=6 in.
h=6 in.
and rectangle [tex]A_2=w\cdot l[/tex]
[tex]w=2\frac12 in. \\l=6+6+6+8+10 = 36 in. [/tex]
[tex]A=2A_1+A_2=2\cdot\frac{a+b}2\cdot h+w\cdot l=(a+b)\cdot h+w\cdot l\\\\A=(14+6)\cdot 6+2\frac12\cdot 36= 120+90=210in.^2=1354.836cm^2\approx1355cm^2[/tex]
