December 30, 2022

Distance Between Two Points - Formula, Derivation, Examples

The theory of length is important in both math and routine life. From easily measuring the length of a line to figuring out the quickest route between two locations, understanding the distance among two points is important.


In this blog, we will take a look at the formula for distance within two points, go through a few examples, and discuss real-life uses of this formula.

The Formula for Distance Between Two Points

The distance within two points, usually signified as d, is the extent of the line segment connecting the two extremities.


In math, this could be portrayed by drawing a right triangle and employing the Pythagorean theorem. Per the Pythagorean theorem, the square of the length of the extensive side (the hypotenuse) is equivalent 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 equal the length, d.


In the case of working out the distance within two points, we could represent the extremities as coordinates on a coordinate plane. Let's assume we have 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) represents the length along y-axis, forming a right angle. By considering the square root of the sum of their squares, we obtain the length among the two extremities.


Here is a visual illustration:


Instances of Applications of the Distance Formula

Considering we have the formula for distance, let's look at some instances of how it can be utilized.

Calculating the Length Between Two Points on a Coordinate Plane

Assume we possess two points 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 distance within these two locations as ensues:


d = √((6 - 3)2+ (8 - 4)2)

d = √(32 + 42)

d = √(9 + 16)

d = √(25)

d = 5


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

Calculating the Length Among Two Points on a Map

In addition to working out the length on a coordinate plane, we could further use the distance formula to work out lengths between two points on a map. For instance, suppose we posses a map of a city along a scale of 1 inch = 10 miles.


To figure out the length within two points on the map, such as the airport and the city hall, we can easily measure the length among the two locations utilizing a ruler and change the measurement to miles utilizing the map's scale.


When we calculate the length among these two locations on the map, we figure out it is 2 inches. We change this to miles using the map's scale and find that the real distance within the city hall and the airport is 20 miles.

Calculating the Distance Among Two Locations in Three-Dimensional Space

In addition to calculating lengths in two dimensions, we could further use the distance formula to calculate the distance among two locations in a three-dimensional space. For example, suppose we have 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 distance between these two locations as ensuing:

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


Utilizing this formula, we could calculate the length between any two points in three-dimensional space. For example, if we have two locations A and B with coordinates (1, 2, 3) and (4, 5, 6), individually, we can work out the distance within them as ensues:


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 distance within locations A and B is approximately 3.16 units.

Uses of the Distance Formula

Now once we have observed some examples of utilizing the distance formula, let's explore some of its uses in math and other fields.

Calculating Distances in Geometry

In geometry, the distance formula is used to calculate the length 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 calculate the distances of the sides AB, BC, and AC. These lengths can be utilized to measure other properties of the triangle, for instance its perimeter, area, and interior angles.

Solving Problems in Physics

The distance formula is additionally used in physics to figure out problems concerning acceleration, speed and distance. For instance, if we recognize the initial location and velocity of an object, also the time it requires for the object to move a certain distance, we could use the distance formula to work out the object's final position and speed.

Analyzing Data in Statistics

In statistics, the length formula is usually used to workout the length within data points in a dataset. This is beneficial for clustering algorithms, which group data points which are near to each other, and for dimensionality reduction techniques, this portrays high-dimensional data in a lower-dimensional space.

Go the Distance with Grade Potential

The distance formula is an essential theory in mathematics which enables us to calculate the between two points on a plane or in a three-dimensional space. By utilizing the Pythagorean theorem, we could derive the distance formula and apply it to a variety of scenarios, from measuring distances on a coordinate plane to analyzing data in statistics.


Comprehending the distance formula and its utilizations are crucial for everyone interested in mathematics and its applications in other areas. If you're having difficulties regarding the distance formula or any other math concept, contact Grade Potential tutoring for personalized help. Our experienced teachers will assist you conquer any math topic, from algebra to calculus and furthermore.


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