# Triangle calculator

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

### Obtuse scalene triangle.

Sides: a = 12.77   b = 6.72   c = 6.44331288095

Area: T = 10.1911161856
Perimeter: p = 25.93331288095
Semiperimeter: s = 12.96765644048

Angle ∠ A = α = 151.9177199843° = 151°55'2″ = 2.65114553277 rad
Angle ∠ B = β = 14.34328001573° = 14°20'34″ = 0.25503290867 rad
Angle ∠ C = γ = 13.74° = 13°44'24″ = 0.24398082392 rad

Height: ha = 1.59661099226
Height: hb = 3.03330838857
Height: hc = 3.16334201821

Median: ma = 1.60224760304
Median: mb = 9.54395914183
Median: mc = 9.68217959484

Inradius: r = 0.78659569843
Circumradius: R = 13.56435475308

Vertex coordinates: A[6.44331288095; 0] B[0; 0] C[12.37219712557; 3.16334201821]
Centroid: CG[6.27217000217; 1.0544473394]
Coordinates of the circumscribed circle: U[3.22215644048; 13.17554068023]
Coordinates of the inscribed circle: I[6.24765644048; 0.78659569843]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 28.08328001573° = 28°4'58″ = 2.65114553277 rad
∠ B' = β' = 165.6577199843° = 165°39'26″ = 0.25503290867 rad
∠ C' = γ' = 166.26° = 166°15'36″ = 0.24398082392 rad

# How did we calculate this triangle?

### 1. Input data entered: side a, b and angle γ. ### 2. Calculation of the third side c of the triangle using a Law of Cosines 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. ### 3. The triangle circumference is the sum of the lengths of its three sides ### 4. Semiperimeter of the triangle ### 5. The triangle area using Heron's formula ### 6. Calculate the heights of the triangle from its area. ### 7. Calculation of the inner angles of the triangle using a Law of Cosines    