# 13 19 30 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 19   c = 30

Area: T = 81.82990901819
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 16.68655898881° = 16°41'8″ = 0.29112184812 rad
Angle ∠ B = β = 24.81216315026° = 24°48'42″ = 0.43330446625 rad
Angle ∠ C = γ = 138.5032778609° = 138°30'10″ = 2.41773295099 rad

Height: ha = 12.58990907972
Height: hb = 8.61435884402
Height: hc = 5.45552726788

Median: ma = 24.25438656713
Median: mb = 21.07772389084
Median: mc = 6.32545553203

Inradius: r = 2.64396480704
Circumradius: R = 22.63986483814

Vertex coordinates: A[30; 0] B[0; 0] C[11.8; 5.45552726788]
Centroid: CG[13.93333333333; 1.81884242263]
Coordinates of the circumscribed circle: U[15; -16.95660726743]
Coordinates of the inscribed circle: I[12; 2.64396480704]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 163.3144410112° = 163°18'52″ = 0.29112184812 rad
∠ B' = β' = 155.1888368497° = 155°11'18″ = 0.43330446625 rad
∠ C' = γ' = 41.49772213907° = 41°29'50″ = 2.41773295099 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.