Distance formula

What you'll learn

1. Compute the distance between two points using d = √((x₂−x₁)² + (y₂−y₁)²)
2. Derive the distance formula from the Pythagorean theorem by constructing a right triangle on the coordinate grid
3. Find the perimeter of a polygon given vertex coordinates by summing pairwise distances
4. Determine whether a triangle is right, isosceles, or equilateral by comparing its side lengths computed via the distance formula
5. Solve ACT-style problems where the distance and one endpoint are given, or where three points are given and the closest pair must be identified

Prerequisites

• Pythagorean theorem