A trapezoid looks like a rectangle with 2 traingles attached to the side, yeah? So imagine cutting off those 2 triangles. In the middle you have a rectangle with the dimensions of 14 cm by 16 cm. The area of that rectagle is 224 cm². By subtracting the top base length from the bottom base length, you get the length of the two triangles. So, it would be 28 cm - 14 cm, giving you 14 cm. There were 2 triangles, so cut that length in half and you get 7 cm for the base of one traingle. To find the area of 1 traingle, you would do 1/2 multiplied by 7 multiplied by 16. But you have 2 triangles. so the 1/2 step isn't needed because if you put the two triangles together, you get a new rectangle. Thus, when you add the area of this new rectangle, you get 112 cm². Add this to the original rectangle, and your final area is 336 cm².
