Triangle calculator VC

Please enter the coordinates of the three vertices

Acute isosceles triangle.

Sides: a = 1.41442135624   b = 2.23660679775   c = 2.23660679775

Area: T = 1.5
Perimeter: p = 5.88663495174
Semiperimeter: s = 2.94331747587

Angle ∠ A = α = 36.87698976458° = 36°52'12″ = 0.64435011088 rad
Angle ∠ B = β = 71.56550511771° = 71°33'54″ = 1.24990457724 rad
Angle ∠ C = γ = 71.56550511771° = 71°33'54″ = 1.24990457724 rad

Height: ha = 2.12113203436
Height: hb = 1.34216407865
Height: hc = 1.34216407865

Median: ma = 2.12113203436
Median: mb = 1.5
Median: mc = 1.5

Inradius: r = 0.51096537321
Circumradius: R = 1.1798511302

Vertex coordinates: A[0; 0] B[1; 2] C[2; 1]
Centroid: CG[1; 1]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[0.17698845774; 0.51096537321]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 143.1330102354° = 143°7'48″ = 0.64435011088 rad
∠ B' = β' = 108.4354948823° = 108°26'6″ = 1.24990457724 rad
∠ C' = γ' = 108.4354948823° = 108°26'6″ = 1.24990457724 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     