# 14 20 28 triangle

### Obtuse scalene triangle.

Sides: a = 14   b = 20   c = 28

Area: T = 131.8754940758
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 28.09880547134° = 28°5'53″ = 0.49904035682 rad
Angle ∠ B = β = 42.28659661512° = 42°17'9″ = 0.73880293367 rad
Angle ∠ C = γ = 109.6165979135° = 109°36'58″ = 1.91331597487 rad

Height: ha = 18.83992772512
Height: hb = 13.18774940758
Height: hc = 9.42196386256

Median: ma = 23.30223603955
Median: mb = 19.74884176581
Median: mc = 10.10995049384

Inradius: r = 4.2544030347
Circumradius: R = 14.86325659184

Vertex coordinates: A[28; 0] B[0; 0] C[10.35771428571; 9.42196386256]
Centroid: CG[12.78657142857; 3.14398795419]
Coordinates of the circumscribed circle: U[14; -4.99895757012]
Coordinates of the inscribed circle: I[11; 4.2544030347]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.9021945287° = 151°54'7″ = 0.49904035682 rad
∠ B' = β' = 137.7144033849° = 137°42'51″ = 0.73880293367 rad
∠ C' = γ' = 70.38440208646° = 70°23'2″ = 1.91331597487 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.