Actually, I'm trying to figure out how much concrete to order by using my mulch calculator and need to help please. Here's the deal. . .it is not square. It is more of a triangle shape. The base is 14' wide, the length is 20', but the third side is curved in a bow shape. At the belly of the curve (10' up the 20' side the curved part is 13'). I am going to attach a drawing of the area. Somebody who knows what they are doing please tell me how many yards of concrete to order to fill the area to a depth of 4" and how you got your answer so I'll know for next time. I'm trying to concrete a grass area for more parking room at my house. Thank you for any and all replies.