i found this:
Surface Area of a Rectangular Prism = 2ab + 2bc + 2ac
(a, b, and c are the lengths of the 3 sides)
In words, the surface area of a rectangular prism is the are of the six rectangles that cover it. But we don't have to figure out all six because we know that the top and bottom are the same, the front and back are the same, and the left and right sides are the same.
The area of the top and bottom (side lengths a and c) = a*c. Since there are two of them, you get 2ac. The front and back have side lengths of b and c. The area of one of them is b*c, and there are two of them, so the surface area of those two is 2bc. The left and right side have side lengths of a and b, so the surface area of one of them is a*b. Again, there are two of them, so their combined surface area is 2ab.
how do you determine wether a decimal is a terminating decimal or a repeating decimal
well, repeating decimals just keep on repeating, like 0.0666...the 6 just keeps on repeating. or like .063490634906..the 06349 keeps on repeating.
terminating decimals end, like 0.75. or 025. or 0.125