December 30, 2022

Distance Between Two Points - Formula, Derivation, Examples

The idea of length is vital in both math and routine life. From simply measuring the length of a line to calculating the quickest route among two locations, understanding the distance between two points is vital.


In this article, we will take a look at the formula for distance between two locations, go through a few examples, and discuss realistic applications of this formula.

The Formula for Length Between Two Locations

The length within two points, frequently denoted as d, is the length of the line segment connecting the two points.


In math, this could be depicted by drawing a right triangle and using the Pythagorean theorem. According to Pythagorean theorem, the square of the length of the longest side (the hypotenuse) is equal to the sum of the squares of the distances of the two other sides.


The formula for the Pythagorean theorem is a2 + b2 = c2. Consequently, √c2 will as same as the distance, d.


In the case of working out the length between two locations, we could represent the points as coordinates on a coordinate plane. Let's assume we possess point A with coordinates (x1, y1) and point B at (x2, y2).


We could then utilize the Pythagorean theorem to derive the ensuing formula for distance:

d = √((x2 - x1)2 + (y2 - y1)2)


In this formula, (x2 - x1) represents the length on the x-axis, and (y2 - y1) depicts the length along y-axis, creating a right angle. By taking the square root of the sum of their squares, we obtain the distance between the two extremities.


Here is a graphical representation:


Examples of Applications of the Distance Formula

Once we possess the formula for distance, let's look at few examples of how it can be utilized.

Working out the Distance Between Two Points on a Coordinate Plane

Imagine we have two locations on a coordinate plane, A with coordinates (3, 4) and B with coordinates (6, 8). We will utilize the distance formula to find the distance between these two points as follows:


d = √((6 - 3)2+ (8 - 4)2)

d = √(32 + 42)

d = √(9 + 16)

d = √(25)

d = 5


Hence, the span within points A and B is 5 units.

Calculating the Distance Between Two Locations on a Map

In addition to finding distances on a coordinate plane, we can further utilize the distance formula to calculate distances within two locations on a map. For example, assume we have a map of a city with a scale of 1 inch = 10 miles.


To find the distance within two locations on the map, similar to the city hall and the airport, we could easily measure the length within the two points utilizing a ruler and convert the measurement to miles using the map's scale.


While we calculate the distance between these two points on the map, we find it is 2 inches. We change this to miles using the map's scale and find out that the actual length within the airport and the city hall is 20 miles.

Determining the Distance Among Two Points in Three-Dimensional Space

In addition to finding lengths in two dimensions, we can also utilize the distance formula to work out the length between two points in a three-dimensional space. For instance, suppose we possess two points, A and B, in a three-dimensional space, with coordinates (x1, y1, z1) and (x2, y2, z2), individually.


We will utilize the distance formula to work out the length between these two points as follows:

d = √((x2 - x1)2 + (y2 - y1)2 + (z2 - z1)2)


Using this formula, we can identify the distance among any two locations in three-dimensional space. For instance, if we have two points A and B with coordinates (1, 2, 3) and (4, 5, 6), each, we could work out the length between them as follows:


d = √((4 - 1)2 + (5 - 2)2 + (6 - 3)2)

d = √(32 + 32 + 32)

d = √(9 + 9 + 9)

d = √(27)

d = 3.16227766


Thus, the distance within locations A and B is roughly 3.16 units.

Uses of the Distance Formula

Now that we have looked at few instances of utilizing the distance formula, let's examine few of its uses in mathematics and other areas.

Measuring Length in Geometry

In geometry, the distance formula is utilized to calculate the length of line segments and the sides of triangles. For instance, in a triangle with vertices at points A, B, and C, we use the distance formula to find the distances of the sides AB, BC, and AC. These lengths can be utilized to measure other properties of the triangle, such as its area, perimeter and its interior angles.

Solving Problems in Physics

The distance formula is further utilized in physics to solve questions involving speed, distance and acceleration. For example, if we know the original position and velocity of an object, as well as the time it requires for the object to transport a specific distance, we can use the distance formula to calculate the object's ultimate location and speed.

Analyzing Data in Statistics

In statistics, the distance formula is usually utilized to calculate the distances between data points in a dataset. This is beneficial for clustering algorithms, which group data points that are close to each other, and for dimensionality reduction techniques, which depicts high-dimensional data in a lower-dimensional space.

Go the Distance with Grade Potential

The distance formula is ac crucial concept in math which allows us to work out the within two points on a plane or in a three-dimensional space. By using the Pythagorean theorem, we can obtain the distance formula and apply it to a magnitude of scenarios, from calculating length on a coordinate plane to analyzing data in statistics.


Comprehending the distance formula and its utilizations are essential for anyone fascinated in math and its applications in other fields. If you're struggling with the distance formula or any other math concept, contact Grade Potential tutoring for tailored help. Our expert instructors will assist you conquer any mathematics topic, from algebra to calculus and furthermore.


Contact us right now to know more and schedule your first tutoring session.