Pythagoras’ theorem is the formula used to calculate any side of a right-angled triangle. The concept is that the square of the hypotenuse is equal to the sum of the squares on the other two sides. Assigning letters: a, b and c, with c being the hypotenuse, you are able to work out the length of each side based on the formula: [a2 + b2 = c2]. As this only works for right-angled triangles, this can also be used to determine whether a specific triangle has a right -angle or not, as both sides of the formula will not be equal.How this can they be applied to the distance between two points is by connecting the two points together to make a hypotenuse and then using this to make a right-angled triangle. By knowing the length of the other sides, the distance between the two points can be calculated.