Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 11.70546999107   b = 6.70882039325   c = 5.09990195136

Area: T = 4.5
Perimeter: p = 23.51219233568
Semiperimeter: s = 11.75659616784

Angle ∠ A = α = 164.7454881297° = 164°44'42″ = 2.87553406044 rad
Angle ∠ B = β = 8.67331740479° = 8°40'23″ = 0.15113754437 rad
Angle ∠ C = γ = 6.58219446552° = 6°34'55″ = 0.11548766054 rad

Height: ha = 0.76989218919
Height: hb = 1.34216407865
Height: hc = 1.76550452162

Median: ma = 1.11880339887
Median: mb = 8.38215273071
Median: mc = 9.19223881554

Inradius: r = 0.38327845074
Circumradius: R = 22.24223519939

Vertex coordinates: A[-7; 3] B[-8; -2] C[-4; 9]
Centroid: CG[-6.33333333333; 3.33333333333]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.5099365104; 0.38327845074]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 15.25551187031° = 15°15'18″ = 2.87553406044 rad
∠ B' = β' = 171.3276825952° = 171°19'37″ = 0.15113754437 rad
∠ C' = γ' = 173.4188055345° = 173°25'5″ = 0.11548766054 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     