# Triangle calculator VC

Please enter the coordinates of the three vertices

### Acute isosceles triangle.

Sides: a = 7.21111025509   b = 8.06222577483   c = 8.06222577483

Area: T = 26
Perimeter: p = 23.33656180475
Semiperimeter: s = 11.66878090238

Angle ∠ A = α = 53.13301023542° = 53°7'48″ = 0.9277295218 rad
Angle ∠ B = β = 63.43549488229° = 63°26'6″ = 1.10771487178 rad
Angle ∠ C = γ = 63.43549488229° = 63°26'6″ = 1.10771487178 rad

Height: ha = 7.21111025509
Height: hb = 6.45498061986
Height: hc = 6.45498061986

Median: ma = 7.21111025509
Median: mb = 6.5
Median: mc = 6.5

Vertex coordinates: A[1; 1] B[9; 2] C[5; 8]
Centroid: CG[5; 3.66766666667]
Coordinates of the circumscribed circle: U[0; 0]
Coordinates of the inscribed circle: I[1.11441766182; 2.22883532364]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 126.8769897646° = 126°52'12″ = 0.9277295218 rad
∠ B' = β' = 116.5655051177° = 116°33'54″ = 1.10771487178 rad
∠ C' = γ' = 116.5655051177° = 116°33'54″ = 1.10771487178 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    