# Triangle calculator VC

Please enter the coordinates of the three vertices

### Obtuse isosceles triangle.

Sides: a = 2.23660679775   b = 4.24326406871   c = 2.23660679775

Area: T = 1.5
Perimeter: p = 8.71547766421
Semiperimeter: s = 4.35773883211

Angle ∠ A = α = 18.43549488229° = 18°26'6″ = 0.32217505544 rad
Angle ∠ B = β = 143.1330102354° = 143°7'48″ = 2.49880915448 rad
Angle ∠ C = γ = 18.43549488229° = 18°26'6″ = 0.32217505544 rad

Height: ha = 1.34216407865
Height: hb = 0.70771067812
Height: hc = 1.34216407865

Median: ma = 3.20215621187
Median: mb = 0.70771067812
Median: mc = 3.20215621187

Vertex coordinates: A[1; 0] B[2; 2] C[4; 3]
Centroid: CG[2.33333333333; 1.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[-0.45989905358; 0.34442429018]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.5655051177° = 161°33'54″ = 0.32217505544 rad
∠ B' = β' = 36.87698976458° = 36°52'12″ = 2.49880915448 rad
∠ C' = γ' = 161.5655051177° = 161°33'54″ = 0.32217505544 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    