# 13 19 28 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 19   c = 28

Area: T = 105.9254501415
Perimeter: p = 60
Semiperimeter: s = 30

Angle ∠ A = α = 23.46664751452° = 23°27'59″ = 0.41095672551 rad
Angle ∠ B = β = 35.59215293953° = 35°35'30″ = 0.62111893738 rad
Angle ∠ C = γ = 120.9421995459° = 120°56'31″ = 2.11108360247 rad

Height: ha = 16.29660771408
Height: hb = 11.15499475174
Height: hc = 7.56660358154

Median: ma = 23.02771578793
Median: mb = 19.6533244007
Median: mc = 8.30766238629

Inradius: r = 3.53108167138
Circumradius: R = 16.32329467867

Vertex coordinates: A[28; 0] B[0; 0] C[10.57114285714; 7.56660358154]
Centroid: CG[12.85771428571; 2.52220119385]
Coordinates of the circumscribed circle: U[14; -8.39327702101]
Coordinates of the inscribed circle: I[11; 3.53108167138]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 156.5343524855° = 156°32'1″ = 0.41095672551 rad
∠ B' = β' = 144.4088470605° = 144°24'30″ = 0.62111893738 rad
∠ C' = γ' = 59.05880045405° = 59°3'29″ = 2.11108360247 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.