# 12 13 22 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 13   c = 22

Area: T = 65.24113787408
Perimeter: p = 47
Semiperimeter: s = 23.5

Angle ∠ A = α = 27.14443226171° = 27°8'40″ = 0.47437578029 rad
Angle ∠ B = β = 29.62204957505° = 29°37'14″ = 0.51769751769 rad
Angle ∠ C = γ = 123.2355181632° = 123°14'7″ = 2.15108596738 rad

Height: ha = 10.87435631235
Height: hb = 10.03771351909
Height: hc = 5.9311034431

Median: ma = 17.04440605491
Median: mb = 16.48548415218
Median: mc = 5.95881876439

Inradius: r = 2.77662288826
Circumradius: R = 13.15111629055

Vertex coordinates: A[22; 0] B[0; 0] C[10.43218181818; 5.9311034431]
Centroid: CG[10.81106060606; 1.9777011477]
Coordinates of the circumscribed circle: U[11; -7.20878489001]
Coordinates of the inscribed circle: I[10.5; 2.77662288826]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 152.8565677383° = 152°51'20″ = 0.47437578029 rad
∠ B' = β' = 150.3879504249° = 150°22'46″ = 0.51769751769 rad
∠ C' = γ' = 56.76548183677° = 56°45'53″ = 2.15108596738 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.