Step-by-step explanation:
For two points (x₁, y₁) and (x₂, y₂), the distance between them is:
d² = (x₁ − x₂)² + (y₁ − y₂)²
The order of points 1 and 2 don't matter. You can switch it:
d² = (x₂ − x₁)² + (y₂ − y₁)²
This is basically the Pythagorean theorem for a coordinate system.
Let's do an example. If you have points (1, 2) and (4, 6), then the distance between them is:
d² = (4 − 1)² + (6 − 2)²
d² = 3² + 4²
d² = 9 + 16
d² = 25
d = 5
If you have points with negative coordinates, remember that subtracting a negative is the same as adding a positive.
For example, the distance between (-1, -2) and (4, 10) is:
d² = (4 − (-1))² + (10 − (-2))²
d² = (4 + 1)² + (10 + 2)²
d² = 5² + 12²
d² = 25 + 144
d² = 169
d = 13