## Enter Side (a)

Given an equilateral triangle with side (a) equal to 9

Calculate the other relevant items in this triangle

P = 3a

P = 3 x 9

P = 27

##### Calculate Semiperimeter s:

 s  = P 2

 s  = 27 2

s = 13.5

##### Calculate Area (A):

 A  = a2√3 4

 A  = 92√3 4

 A  = 81√3 4

 A  = 140.296 4

A = 35.07402885327

##### Calculate Bisector

 ha-ma-ta  = a√3 2

 ha-ma-ta  = 15.5885 2

ha-ma-ta = 7.7942286340599

 R  = a√3 3

 R  = 15.5885 3

R = 5.1961524227066

 r  = a√3 6

 r  = 15.5885 6

r = 2.5980762113533

P = 27
s = 13.5
A = 9

#### You have 2 free calculationss remaining

P = 27
s = 13.5
A = 9
##### How does the Equilateral Triangle Calculator work?
Free Equilateral Triangle Calculator - Given a side (a), this calculates the following items of the equilateral triangle:
* Perimeter (P)
* Semi-Perimeter (s)
* Area (A)
* altitudes (ha,hb,hc)
* medians (ma,mb,mc)
* angle bisectors (ta,tb,tc)
This calculator has 1 input.

### What 3 formulas are used for the Equilateral Triangle Calculator?

P = 3a
s = ½P
A = a22√3/4

For more math formulas, check out our Formula Dossier

### What 6 concepts are covered in the Equilateral Triangle Calculator?

altitude
segment from the vertex of a triangle ot the other side of the triangle
area
Number of square units covering the shape
equilateral triangle
A triangle with 3 equal sides
perimeter
The distance around a shape or object