Triangle calculator VC

Please enter the coordinates of the three vertices

Right isosceles triangle.

Sides: a = 21.63333076528   b = 15.29770585408   c = 15.29770585408

Area: T = 117
Perimeter: p = 52.22774247343
Semiperimeter: s = 26.11437123672

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

Height: ha = 10.81766538264
Height: hb = 15.29770585408
Height: hc = 15.29770585408

Median: ma = 10.81766538264
Median: mb = 17.10326313765
Median: mc = 17.10326313765

Inradius: r = 4.48804047144
Circumradius: R = 10.81766538264

Vertex coordinates: A[4; 5] B[7; -10] C[-11; 2]
Centroid: CG[0; -1]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[4.48804047144; 4.48804047144]

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