Answer: What is the distance formula is that it's the formula used in Mathematics such as Pre-Algebra, Algebra 1, Geometry, Algebra 2, Trigonometry, and Pre-Calculus, also Calculus to help you find the distance between 2 points in a coordinate plane or the length of a segment. How you do the distance formula is you subtract the 2nd x coordinate by the 1st one, next you add the 2nd y coordinate to the 1st one, then the answer you get you evaluate them using the exponent of 2, lastly you add that answer and square root the answer you get to the approximate or closest decimal or whole number.