Triangle calculator VC

Please enter the coordinates of the three vertices

Right isosceles triangle.

Sides: a = 6.40331242374   b = 9.05553851381   c = 6.40331242374

Area: T = 20.5
Perimeter: p = 21.8621633613
Semiperimeter: s = 10.93108168065

Angle ∠ A = α = 45° = 0.78553981634 rad
Angle ∠ B = β = 90° = 1.57107963268 rad
Angle ∠ C = γ = 45° = 0.78553981634 rad

Height: ha = 6.40331242374
Height: hb = 4.52876925691
Height: hc = 6.40331242374

Median: ma = 7.15989105316
Median: mb = 4.52876925691
Median: mc = 7.15989105316

Inradius: r = 1.87554316684
Circumradius: R = 4.52876925691

Vertex coordinates: A[-2; 9] B[3; 5] C[-1; 0]
Centroid: CG[0; 4.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0; 1.87554316684]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 135° = 0.78553981634 rad
∠ B' = β' = 90° = 1.57107963268 rad
∠ C' = γ' = 135° = 0.78553981634 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     