reply to this post and make few addtion to clarify The inverse square law states that the intensity of radiation is inversely proportional to the square of the distance from the source of the radiation. The farther away the x-ray beam, the lesser radiation received by the receptor. For example, a hypersthenic patient has a bigger body size than a sthenic patient. To include all required parts of their abdomen, we need to increase the distance of the x-ray beam to increase the target area. Since we increased the distance we also have to increase the mAs to make up for the loss of intensity because if not, the x-ray will come out blurry