December 30, 2022

Distance Between Two Points - Formula, Derivation, Examples

The theory of length is important in both math and everyday life. From straightforward measuring the extent of a line to working out the quickest route between two points, comprehending the length among two points is crucial.


In this blog, we will explore the formula for distance within two locations, work on a few examples, and discuss realistic uses of this formula.

The Formula for Distance Within Two Points

The length between two points, usually signified as d, is the length of the line segment linking the two extremities.


Mathematically, this can be portrayed 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 total of the squares of the distances of the two other sides.


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


In instance of finding the distance within two points, we could depict the extremities as coordinates on a coordinate plane. Let's say we have point A with coordinates (x1, y1) and point B at (x2, y2).


We can then use the Pythagorean theorem to derive the following formula for distance:

d = √((x2 - x1)2 + (y2 - y1)2)


In this formula, (x2 - x1) depicts the length on the x-axis, and (y2 - y1) represents the length along y-axis, forming a right angle. By considering the square root of the sum of their squares, we get the length between the two points.


Here is a visual depiction:


Instances of Using 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 Length Among the Two Points on a Coordinate Plane

Assume we possess two locations on a coordinate plane, A with coordinates (3, 4) and B with coordinates (6, 8). We will employ the distance formula to figure out the length between these two locations as follows:


d = √((6 - 3)2+ (8 - 4)2)

d = √(32 + 42)

d = √(9 + 16)

d = √(25)

d = 5


Therefore, the span between points A and B is 5 units.

Calculating the Length Among Two Extremities on a Map

In addition to figuring out the length on a coordinate plane, we could further use the distance formula to figure out distances within two points on a map. For example, assume we have a map of a city along a scale of 1 inch = 10 miles.


To find the length within two points on the map, such as the airport and the city hall, we can easily calculate the length within the two points utilizing a ruler and convert the measurement to miles using the map's scale.


Once we measure the distance among these two locations on the map, we find it is 2 inches. We change this to miles using the map's scale and find that the true length between the city hall and the airport is 20 miles.

Determining the Distance Within Two Points in Three-Dimensional Space

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


We will utilize the distance formula to find the distance within these two points as follows:

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


Using this formula, we can calculate the length among any two locations in three-dimensional space. For instance, if we have two locations A and B with coordinates (1, 2, 3) and (4, 5, 6), individually, we could work out the distance among 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


Hence, the length between locations A and B is just about 3.16 units.

Uses of the Distance Formula

Now that we have looked at some instances of utilizing the distance formula, let's explore some of its Utilizations in mathematics and other areas.

Measuring Length in Geometry

In geometry, the distance formula is utilized to calculate the distance of line segments and the sides of triangles. For example, in a triangle with vertices at points A, B, and C, we use the distance formula to figure out the distances of the sides AB, BC, and AC. These lengths can be employed to calculate other characteristics of the triangle, for instance its interior angles, area, perimeter.

Solving Problems in Physics

The distance formula is further used in physics to figure out questions involving speed, distance and acceleration. For example, if we know the first position and velocity of an object, also the time it requires for the object to move a certain length, we can utilize the distance formula to calculate the object's ultimate location and speed.

Analyzing Data in Statistics

In statistics, the distance formula is often utilized to calculate the distances within data points in a dataset. This is useful for clustering algorithms, that segregate data points that are near to each other, and for dimensionality reduction techniques, this depicts high-dimensional data in a lower-dimensional space.

Go the Distance with Grade Potential

The distance formula is an essential theory in math which enables us to calculate the length between two location on a plane or in a three-dimensional space. By utilizing the Pythagorean theorem, we can extract the distance formula and apply it to a assortments of scenarios, from measuring distances on a coordinate plane to analyzing data in statistics.


Comprehending the distance formula and its applications are crucial for anyone fascinated in mathematics and its applications in other areas. If you're having difficulties with the distance formula or any other mathematical theories, reach out to Grade Potential tutoring for tailored assistance. Our expert teachers will assist you conquer any mathematics topic, from algebra to calculus and beyond.


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