# 10 18 22 triangle

### Obtuse scalene triangle.

Sides: a = 10   b = 18   c = 22

Area: T = 88.74111967465
Perimeter: p = 50
Semiperimeter: s = 25

Angle ∠ A = α = 26.6277478393° = 26°37'39″ = 0.46547371695 rad
Angle ∠ B = β = 53.77884533802° = 53°46'42″ = 0.93986110781 rad
Angle ∠ C = γ = 99.59440682269° = 99°35'39″ = 1.7388244406 rad

Height: ha = 17.74882393493
Height: hb = 9.86601329718
Height: hc = 8.06773815224

Median: ma = 19.46879223339
Median: mb = 14.52658390463
Median: mc = 9.53993920142

Inradius: r = 3.55496478699
Circumradius: R = 11.15660361624

Vertex coordinates: A[22; 0] B[0; 0] C[5.90990909091; 8.06773815224]
Centroid: CG[9.3033030303; 2.68991271741]
Coordinates of the circumscribed circle: U[11; -1.85993393604]
Coordinates of the inscribed circle: I[7; 3.55496478699]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 153.3732521607° = 153°22'21″ = 0.46547371695 rad
∠ B' = β' = 126.222154662° = 126°13'18″ = 0.93986110781 rad
∠ C' = γ' = 80.40659317731° = 80°24'21″ = 1.7388244406 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    