# 4 19 22 triangle

### Obtuse scalene triangle.

Sides: a = 4   b = 19   c = 22

Area: T = 26.99895813232
Perimeter: p = 45
Semiperimeter: s = 22.5

Angle ∠ A = α = 7.42197114187° = 7°25'11″ = 0.12994983938 rad
Angle ∠ B = β = 37.83657224233° = 37°50'9″ = 0.66603579312 rad
Angle ∠ C = γ = 134.7454566158° = 134°44'40″ = 2.35217363286 rad

Height: ha = 13.49547906616
Height: hb = 2.84110085603
Height: hc = 2.45435983021

Median: ma = 20.45772725455
Median: mb = 12.63992246598
Median: mc = 8.21658383626

Inradius: r = 1.21995369477
Circumradius: R = 15.4877457734

Vertex coordinates: A[22; 0] B[0; 0] C[3.15990909091; 2.45435983021]
Centroid: CG[8.38663636364; 0.81878661007]
Coordinates of the circumscribed circle: U[11; -10.90223551154]
Coordinates of the inscribed circle: I[3.5; 1.21995369477]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 172.5880288581° = 172°34'49″ = 0.12994983938 rad
∠ B' = β' = 142.1644277577° = 142°9'51″ = 0.66603579312 rad
∠ C' = γ' = 45.2555433842° = 45°15'20″ = 2.35217363286 rad

# How did we calculate this triangle?

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. ### 1. The triangle circumference is the sum of the lengths of its three sides ### 2. Semiperimeter of the triangle ### 3. The triangle area using Heron's formula ### 4. Calculate the heights of the triangle from its area. ### 5. Calculation of the inner angles of the triangle using a Law of Cosines    