# 12 18 22 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 18   c = 22

Area: T = 107.9265900506
Perimeter: p = 52
Semiperimeter: s = 26

Angle ∠ A = α = 33.03301516046° = 33°1'49″ = 0.57664848979 rad
Angle ∠ B = β = 54.84772970332° = 54°50'50″ = 0.9577265919 rad
Angle ∠ C = γ = 92.12325513621° = 92°7'21″ = 1.60878418366 rad

Height: ha = 17.98876500843
Height: hb = 11.99217667229
Height: hc = 9.81114455005

Median: ma = 19.18333260933
Median: mb = 15.26443375225
Median: mc = 10.63301458127

Inradius: r = 4.15109961733
Circumradius: R = 11.00875523524

Vertex coordinates: A[22; 0] B[0; 0] C[6.90990909091; 9.81114455005]
Centroid: CG[9.63663636364; 3.27704818335]
Coordinates of the circumscribed circle: U[11; -0.40876871242]
Coordinates of the inscribed circle: I[8; 4.15109961733]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 146.9769848395° = 146°58'11″ = 0.57664848979 rad
∠ B' = β' = 125.1532702967° = 125°9'10″ = 0.9577265919 rad
∠ C' = γ' = 87.87774486379° = 87°52'39″ = 1.60878418366 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 ### 6. Inradius ### 7. Circumradius ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.