Gradient can be used to specify how steep a slope can be so that it is thought of as safe. This might be for examples such as: Any distance \((d)\) greater than \(250cm\) will be okay. You should ...

To find the perpendicular gradient, find the number which will multiply by 2 to give -1. This is the negative reciprocal close reciprocal The reciprocal of a number is 1 divided by that number.