a rectangular prism has six rectangular faces or sides, its surface area is just the sum of the six faces, you can calculate the surface area with the formula 2 length width + 2 * width * height + 2 * height * length, where length, width and height.
By definition of normal distribution, ≈68% of the data is within 1 standard deviation of the mean. Therefore 68% of IQs are between 85 and 115, and half of that is on the lower end, 85 to 100.
