December 30, 2022

Distance Between Two Points - Formula, Derivation, Examples

The idea of length is vital in both math and everyday life. From easily measuring the length of a line to working out the quickest route among two extremities, understanding the distance among two points is crucial.


In this blog article, we will take a look at the formula for distance within two extremities, work on a few examples, and discuss real-life uses of this formula.

The Formula for Length Between Two Points

The distance among two locations, frequently denoted as d, is the extent of the line segment connecting the two locations.


Mathematically, this can be depicted 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 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 result, √c2 will as same as the distance, d.


In the circumstance of working out the distance within two locations, we could depict the points as coordinates on a coordinate plane. Let's say we possess point A with coordinates (x1, y1) and point B at (x2, y2).


We can then utilize the Pythagorean theorem to acquire the following formula for distance:

d = √((x2 - x1)2 + (y2 - y1)2)


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


Here is a graphical representation:


Instances of Using the Distance Formula

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

Working out the Distance Among the Two Locations on a Coordinate Plane

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


d = √((6 - 3)2+ (8 - 4)2)

d = √(32 + 42)

d = √(9 + 16)

d = √(25)

d = 5


Hence, the length between points A and B is 5 units.

Calculating the Length Between Two Extremities on a Map

In addition to working out the distances on a coordinate plane, we can also use the distance formula to figure out distances between two locations on a map. For instance, suppose we have a map of a city with a scale of 1 inch = 10 miles.


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


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

Calculating the Length Between Two Locations in Three-Dimensional Space

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


We will use the distance formula to figure out the length within these two locations as follows:

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


Utilizing this formula, we could determine the length within any two points in three-dimensional space. For instance, if we have two points A and B with coordinates (1, 2, 3) and (4, 5, 6), individually, we can figure out the distance within 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


Therefore, the distance between locations A and B is approximately 3.16 units.

Utilizations of the Distance Formula

Now that we have observed some examples of utilizing the distance formula, let's explore some of its applications in mathematics and other fields.

Calculating Length in Geometry

In geometry, the distance formula is used 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 utilize the distance formula to find the distances of the sides AB, BC, and AC. These distances could be used to calculate other characteristics of the triangle, such as its perimeter, area, and interior angles.

Solving Problems in Physics

The distance formula is also utilized in physics to work out problems involving speed, distance and acceleration. For instance, if we know the first location and velocity of an object, in addition to the time it takes for the object to transport a specific length, we can use the distance formula to figure out the object's ultimate location and speed.

Analyzing Data in Statistics

In statistics, the length formula is often used to figure out the distances between data points in a dataset. This is beneficial for clustering algorithms, which segregate data points which are close to each other, and for dimensionality reduction techniques, which portrays high-dimensional data in a lower-dimensional space.

Go the Distance with Grade Potential

The distance formula is an important concept in mathematics that allows us to calculate the length within two points on a plane or in a three-dimensional space. By using the Pythagorean theorem, we could derive the distance formula and implement it to a assortments of situations, from calculating distances on a coordinate plane to analyzing data in statistics.


Understanding the distance formula and its uses are important for everyone interested in mathematics and its uses in other areas. If you're having difficulties regarding the distance formula or any other math concept, Grade Potential tutoring for customized guidance. Our expert instructors will help you master any mathematics topic, from algebra to calculus and beyond.


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