Triangle calculator VC

Please enter the coordinates of the three vertices

Obtuse scalene triangle.

Sides: a = 9.84988578018   b = 13.60114705087   c = 17.72200451467

Area: T = 66.5
Perimeter: p = 41.17703734572
Semiperimeter: s = 20.58551867286

Angle ∠ A = α = 33.49222693031° = 33°29'32″ = 0.58545503733 rad
Angle ∠ B = β = 49.64879706914° = 49°38'53″ = 0.86765205555 rad
Angle ∠ C = γ = 96.86597600055° = 96°51'35″ = 1.69105217248 rad

Height: ha = 13.50441039963
Height: hb = 9.77883544738
Height: hc = 7.50656242182

Median: ma = 15.00883310198
Median: mb = 12.61994294641
Median: mc = 7.90656941504

Inradius: r = 3.23304783472
Circumradius: R = 8.92439045975

Vertex coordinates: A[-10; -3] B[7; 2] C[3; -7]
Centroid: CG[0; -2.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[2.74546921296; 3.23304783472]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 146.5087730697° = 146°30'28″ = 0.58545503733 rad
∠ B' = β' = 130.3522029309° = 130°21'7″ = 0.86765205555 rad
∠ C' = γ' = 83.14402399945° = 83°8'25″ = 1.69105217248 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     