Latest Qualification Jobs

Check Your Email To Activate the Confirmation Link

Area of an Equilateral Triangle: Formula, Calculator, Derivation with Examples

Area of an Equilateral Triangle

Area of an Equilateral Triangle is measured in unitand the Equilateral triangles are also equi-angular, which denotes, all three internal angles are also equivalent to each other and the only value possible is 60° each.

To solve out questions related to Area of Equilateral Triangle by using Calculator, check this page completely and get Formula for Area of an Equilateral Triangle, Derivation of Area of Equilateral Triangle with examples etc.

Area of an Equilateral Triangle

How To Find Area Of Equilateral Triangle?

This is the Formula to Find Area of Equilateral Triangle as shown below:

Area = √3/4*a2

Where ‘a’ is the length of any side of the triangle

Note that:√3/4 is constant that has the value of approximately 0.433, so the formula simplifies a little to

Approximate Area Of The Equilateral Triangle=0.433ss

How To Find Area Of Right Angled Triangle: Formula with Examples

For Example:

1: Find the area of an equilateral triangle whose side is 7 cm?

Solution: Given, Side of the equilateral triangle = a = 7 cm

Area of an equilateral triangle =√3/4*a2

= √3/4*72cm2
= √3/4*49 cm2
= 21.21762 cm2

2. Find the area of an equilateral triangle whose side is 28 cm?

Solution: Given, Side of the equilateral triangle = a = 28 cm

The Area Of An Equilateral Triangle=√3/4*a2

= √3/4*282cm2
= √3/4*784 cm2
= 339.48196cm2

Formula to Calculate Area, Perimeter, Circumference: Find Area of Circle

How to Calculate Derivation of Area?

As we know that the Formula for Area of Equilateral Triangle is√3/4*a2, then in terms of side length a can be derived directly using the following methods i.e.

  • Pythagorean Theorem
  • Trigonometry

Area of an Equilateral Triangle    

How to use Pythagorean Theorem to find Area of an Equilateral Triangle?

The area of a triangle is half of one side ‘a’ times the height ‘h’ from that side:

A = 1/2*ah

The height of an equilateral triangle can be found using the Pythagorean Theorem is:

(a/2)2 + h2 = a2

So that,

h= √3/4*a

And, replacing h into the area formula (1/2)ah gives the area formula for the equilateral triangle:

A = √3/4*a2

Get Maths Vedic/Basic Formulas Free List: Maths Formulas

How To Use Trigonometry To Find Area Of Equilateral Triangle?

Now, in this condition, the area of a triangle with any two sides a and b, and an angle C between them is:

A = 1/2*ab*sinC

Each angle of an equilateral triangle is 60°, so

A = 1/2*ab*sin600

The sine of 600 is √3/2. Thus

A = 1/2ab *√3/2 = √3/4ab = √3/4a2

For Example:

1: A farmer needs to replant a triangular section of crops that died unexpectedly. One side of the triangle measures 186 yards, another measures 205 yards, and the angle formed by these two sides is 148∘. What is the area of the section of crops that needs to be replanted?


Use K=1/2bcsinA,


So, Area of a Equilateral Triangle that needs to be replaced is 10102.9 square yards.

Read Here: How to Prepare for Maths

How To Find Perimeter Of Equilateral Triangle When Area Is Given?

Suppose, ΔABC is an equilateral triangle with area 55 then Perimeter is 33.8. Explanation is provided below:


To find out the perimeter of an equilateral triangle, firstly, we must find the length of the sides and this can be done by using the Area Of An Equilateral Triangle Formula:

Area = √3/4*a2

Where ‘a’ is the side of the triangle, because the sides of the equilateral triangle are equal, the perimeter is equal to 3a.

Read Now: Ways to Improve Math Skills

Area Of Equilateral Triangle Proof

Check here the Area Of Equilateral Triangle Formula Proof in following three steps as described below:

Step 1:

Since all the 3 sides of the triangle are same,

AB = BC = CA = a

Step 2:

Find the altitude of the △ABC.

First of all, Draw a perpendicular from point A to base BC, AD ⊥ BC

Now By using Pythagoras theoremIn △ADC

h2 = AC2 – DC2
= a2 – (a/2)2 [Because, DC = a/2]
= a2 – a2/4
h = √3a/2

Step 3:

We know that, Area of a triangle = 1/2 * Base * Height

= √3/4*a2

START NOW: Mathematics Quiz

Final Note:

We expect that, information provided above related to Area of an Equilateral Triangle is helpful for you. So those, who don’t know What Is the Area of Equilateral Triangle, must check out this page.

Please subscribe us to get more Maths formula, tips and tricks to create your own Notes etc. Follow us on social media for receiving updated information regarding Area Of Triangle Equilateral etc. Thank You ForVisiting Us….

Something That You Should Put an Eye On

Surface Area of SphereVolume And Surface Area Questions
Area Of A TrapeziumProfit And Loss Questions And Answers
Aptitude Questions & AnswersAptitude Formulas
Percentage Problems and SolutionsRatio and Proportion
Probability Questions & AnswersTime And Distance Problems

Filed in: Formula

Leave a Reply

Submit Comment