r represents radius or the distance between two points, the pythagorean expression will be
r² = Δx² + Δy²
Δ means the change, Δx means the change of x, Δy means the change of y
Given:
(x₁,y₁) = (-5,-1)
(x₂,y₂) = (0,2)
Input the numbers to the expression
r² = Δx² + Δy²
r² = (x₂ - x₁)² + (y₂ - y₁)²
r² = (0 + 5)² + (2 + 1)²
r² = 5² + 3²
r² = 25 + 9
r² = 34
r = √34
The distance is √34 unit length