Triangle calculator VC

Please enter the coordinates of the three vertices

Acute scalene triangle.

Sides: a = 7.28801098893   b = 9.22195444573   c = 8.6022325267

Area: T = 29.5
Perimeter: p = 25.10219796136
Semiperimeter: s = 12.55109898068

Angle ∠ A = α = 48.06664855011° = 48°3'59″ = 0.83989184319 rad
Angle ∠ B = β = 70.40877181089° = 70°24'28″ = 1.22988464998 rad
Angle ∠ C = γ = 61.52657963899° = 61°31'33″ = 1.07438277219 rad

Height: ha = 8.1044273273
Height: hb = 6.39994485057
Height: hc = 6.85986106859

Median: ma = 8.1399410298
Median: mb = 6.5
Median: mc = 7.10663352018

Vertex coordinates: A[-7; 1] B[0; -4] C[2; 3]
Centroid: CG[-1.66766666667; 0]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[0.83765874056; 2.35504122347]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 131.9343514499° = 131°56'1″ = 0.83989184319 rad
∠ B' = β' = 109.5922281891° = 109°35'32″ = 1.22988464998 rad
∠ C' = γ' = 118.474420361° = 118°28'27″ = 1.07438277219 rad

How did we calculate this triangle?

1. We compute side a from coordinates using the Pythagorean theorem 2. We compute side b from coordinates using the Pythagorean theorem 3. We compute side c from coordinates using the Pythagorean theorem Now we know the lengths of all three sides of the triangle and the triangle is uniquely determined. Next we calculate another its characteristics - same procedure as calculation of the triangle from the known three sides SSS. 4. The triangle circumference is the sum of the lengths of its three sides 5. Semiperimeter of the triangle 6. The triangle area using Heron's formula 7. Calculate the heights of the triangle from its area. 8. Calculation of the inner angles of the triangle using a Law of Cosines    