Triangle calculator VC

Please enter the coordinates of the three vertices

Acute scalene triangle.

Sides: a = 6.32545553203   b = 11.18803398875   c = 9.84988578018

Area: T = 31
Perimeter: p = 27.35437530096
Semiperimeter: s = 13.67768765048

Angle ∠ A = α = 34.26773354433° = 34°16'2″ = 0.59880778294 rad
Angle ∠ B = β = 84.47224598483° = 84°28'21″ = 1.47443225516 rad
Angle ∠ C = γ = 61.26602047083° = 61°15'37″ = 1.06991922726 rad

Height: ha = 9.80330607465
Height: hb = 5.54554485842
Height: hc = 6.29551462238

Median: ma = 10.05498756211
Median: mb = 6.10332778079
Median: mc = 7.63221687612

Inradius: r = 2.26765993942
Circumradius: R = 5.61662855956

Vertex coordinates: A[0; -3] B[-4; 6] C[2; 8]
Centroid: CG[-0.66766666667; 3.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[0.21993483285; 2.26765993942]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 145.7332664557° = 145°43'58″ = 0.59880778294 rad
∠ B' = β' = 95.52875401517° = 95°31'39″ = 1.47443225516 rad
∠ C' = γ' = 118.7439795292° = 118°44'23″ = 1.06991922726 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     