The attached drawing is for a privacy screen to go in our yard. The frame is made by 2"x4" (1.5" x 3.5") cedar laying on its side so you are viewing the 1.5" dimension. The 2x4's in the middle are centered vertically and horizontally. The overall width is 7 feet (84") and the overall height is 5 feet (60") so the total space inside is 79.5" horizontally (84 - 1.5 - 1.5 - 1.5) and 55.5" vertically (60" - 1.5 - 1.5 - 1.5) and the dimension of each window is 39.75" horizontally and 27.75" vertically. The slats, which are 1.5" wide and oriented at a 45 degree angle, are 1.5" wide. The spacing between successive slats is not determined yet so it needs to be a variable called spacing. It may be 1/4" or 1/2" or zero. The slats will be attached so that every other slat is on the opposite side of the 2x4 so even if the spacing is zero, the slats will not be touching each other as they will be separated by about 3/4" on the Z axis.
I want to make an Excel workbook which will take all the data above and calculate how many feet of the slat material I will need.