Express the area of an equilateral triangle

Express the area of an equilateral triangle as a function of the length of a side.


Let “x” represent the side length of the equilateral triangle. If we let “h” represent the height of the  triangle, we can use Pythagorean theorem to figure it out.



Expanding this, we get


and solving for h, we have


The area of a triangle is equal to A=\frac{1}{2}(base)(height). If we write area as a function of length, then we have

A(x)=\frac{1}{2}(x)(\frac{\sqrt{3}}{2}x)=\frac{\sqrt{3}}{4}x^{2} and the domain is x>0.


See a mistake? Comment below so we can fix it!

Leave a comment

Your email address will not be published. Required fields are marked *