Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 10.77703296143   b = 7.07110678119   c = 14.21326704036

Area: T = 37
Perimeter: p = 32.05440678297
Semiperimeter: s = 16.02770339148

Angle ∠ A = α = 47.42195092167° = 47°25'10″ = 0.82876265655 rad
Angle ∠ B = β = 28.90991836511° = 28°54'33″ = 0.50545604388 rad
Angle ∠ C = γ = 103.6711307132° = 103°40'17″ = 1.80994056493 rad

Height: ha = 6.87107275126
Height: hb = 10.46551803616
Height: hc = 5.2076621831

Median: ma = 9.84988578018
Median: mb = 12.10437184369
Median: mc = 5.70108771255

Inradius: r = 2.30985993451
Circumradius: R = 7.31435454745

Vertex coordinates: A[0; 5] B[9; -6] C[-1; -2]
Centroid: CG[2.66766666667; -1]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[4.1880436652; 2.30985993451]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 132.5880490783° = 132°34'50″ = 0.82876265655 rad
∠ B' = β' = 151.0910816349° = 151°5'27″ = 0.50545604388 rad
∠ C' = γ' = 76.32986928678° = 76°19'43″ = 1.80994056493 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     