# Triangle calculator

Please enter what you know about the triangle:
You have entered side a, b and c.

### Obtuse scalene triangle.

Sides: a = 40   b = 55   c = 85

Area: T = 887.4121967465
Perimeter: p = 180
Semiperimeter: s = 90

Angle ∠ A = α = 22.31114770869° = 22°18'41″ = 0.38994087361 rad
Angle ∠ B = β = 31.46769762933° = 31°28'1″ = 0.5499202342 rad
Angle ∠ C = γ = 126.222154662° = 126°13'18″ = 2.20329815755 rad

Height: ha = 44.37105983732
Height: hb = 32.27695260896
Height: hc = 20.88802815874

Median: ma = 68.73986354243
Median: mb = 60.46769331122
Median: mc = 22.5

Inradius: r = 9.86601329718
Circumradius: R = 52.68112818781

Vertex coordinates: A[85; 0] B[0; 0] C[34.11876470588; 20.88802815874]
Centroid: CG[39.70658823529; 6.96600938625]
Coordinates of the circumscribed circle: U[42.5; -31.13298483825]
Coordinates of the inscribed circle: I[35; 9.86601329718]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 157.6898522913° = 157°41'19″ = 0.38994087361 rad
∠ B' = β' = 148.5333023707° = 148°31'59″ = 0.5499202342 rad
∠ C' = γ' = 53.77884533802° = 53°46'42″ = 2.20329815755 rad

# How did we calculate this triangle?

### 1. Input data entered: side a, b and c. ### 2. The triangle circumference is the sum of the lengths of its three sides ### 3. Semiperimeter of the triangle ### 4. The triangle area using Heron's formula ### 5. Calculate the heights of the triangle from its area. ### 6. Calculation of the inner angles of the triangle using a Law of Cosines    