# 12 22 30 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 22   c = 30

Area: T = 113.137708499
Perimeter: p = 64
Semiperimeter: s = 32

Angle ∠ A = α = 20.05499757242° = 20°3' = 0.35499380913 rad
Angle ∠ B = β = 38.9422441269° = 38°56'33″ = 0.68796738189 rad
Angle ∠ C = γ = 121.0087583007° = 121°27″ = 2.11219807434 rad

Height: ha = 18.85661808316
Height: hb = 10.28551895445
Height: hc = 7.54224723327

Median: ma = 25.61224969497
Median: mb = 20.02549843945
Median: mc = 9.43439811321

Inradius: r = 3.53655339059
Circumradius: R = 17.50108928344

Vertex coordinates: A[30; 0] B[0; 0] C[9.33333333333; 7.54224723327]
Centroid: CG[13.11111111111; 2.51441574442]
Coordinates of the circumscribed circle: U[15; -9.01656114601]
Coordinates of the inscribed circle: I[10; 3.53655339059]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 159.9550024276° = 159°57' = 0.35499380913 rad
∠ B' = β' = 141.0587558731° = 141°3'27″ = 0.68796738189 rad
∠ C' = γ' = 58.99224169931° = 58°59'33″ = 2.11219807434 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.