Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 15.03332963784   b = 5.38551648071   c = 10.05498756211

Area: T = 12.5
Perimeter: p = 30.46883368066
Semiperimeter: s = 15.23441684033

Angle ∠ A = α = 152.4887997376° = 152°29'17″ = 2.6611417624 rad
Angle ∠ B = β = 9.52546679718° = 9°31'29″ = 0.16662368163 rad
Angle ∠ C = γ = 17.98773346521° = 17°59'14″ = 0.31439382133 rad

Height: ha = 1.66329752631
Height: hb = 4.64223834544
Height: hc = 2.48875929755

Median: ma = 2.91554759474
Median: mb = 12.5
Median: mc = 10.11218742081

Vertex coordinates: A[2; -5] B[-8; -4] C[7; -3]
Centroid: CG[0.33333333333; -4]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[4.8990322729; 0.82105239478]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 27.51220026239° = 27°30'43″ = 2.6611417624 rad
∠ B' = β' = 170.4755332028° = 170°28'31″ = 0.16662368163 rad
∠ C' = γ' = 162.0132665348° = 162°46″ = 0.31439382133 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    