perimeter of a trapezoid

Note that the two triangles are both right triangles with legs of 3 and 4.....so....he hypotenuse is

sqrt (3^2 + 4^2) =  sqrt (25) = 5

And this is the length of the sides

And we have a rectangle with bottom/top of 8 units

So....the permeter is  2(5) + 2(8)  + 2(4)= 10 + 16 + 8 =  34 cm