Distance Between 2 Points

Here is how to calculate the distance between two points when you know their coordinates:

Let us call the two points A and B

We can run lines down from A, and along from B, to make a Right Angled Triangle.

And with a little help from Pythagoras we know that:

a² + b² = c²

Now label the coordinates of points A and B.

x_A means the x-coordinate of point A
y_A means the y-coordinate of point A

The horizontal distance a is (x_A − x_B)

The vertical distance b is (y_A − y_B)

Now we can solve for c (the distance between the points):

Start with:c² = a² + b²

Put in the calculations for a and b:c² = (x_A − x_B)² + (y_A − y_B)²

And the final result:

Examples

Example 1

Fill in the values:

Example 2

It doesn't matter what order the points are in, because squaring removes any negatives:

Fill in the values: