Triangle given by 3 points (x_{1} , y_{1}), (x_{2} , y_{2}) and (x_{3} , y_{3})

The area is given by: 


Perimeter (P) 

Triangle angles:
We have to remember that if the result of the angle is negative then we have to translate it into
a positive angle by the formula:
angle = 2 · pi angle.


Intersection point of the medians.

Intersection point of the medians (x , y) (centroid  also known as the center of gravity).
The lengths of the medians are:

Intersection point of the triangle altitudes (orthocentre)
After solving the determinants x and y will be:
The lengths of the altitudes are found by the formulas:

Intersection point of the sides perpendicular bisectors (circumcircle)
After solving the determinants, we get the x and y coordinates:
The circumcircle radius can be found by calculating the distance of the center point (x , y) from any one of the triangle vertices:

Intersection point (x , y) of the angles bisectors (incircle)

We denote a, b and c as the lengths of the triangle sides.
The incircle radius can be found by calculating the distance of the center point (x , y) from one of the sides of the triangle:
