write the formula used to find the area of the trapezoid

The area is given by
[tex]\begin{gathered} A=\frac{1}{2}(A+B)H,\text{ when c is the length of the hypotenuse.} \\ A=\frac{1}{2}(A+(\sqrt[]{C^2-H^2}+A)H \end{gathered}[/tex]Where,
[tex]A=\text{ 6m, B=}\sqrt[]{10^2-8^2}+6=12m,and\text{ H =}8m[/tex]