# 19 19 28 triangle

### Obtuse isosceles triangle.

Sides: a = 19   b = 19   c = 28

Area: T = 179.8333256101
Perimeter: p = 66
Semiperimeter: s = 33

Angle ∠ A = α = 42.5376898363° = 42°32'13″ = 0.742240893 rad
Angle ∠ B = β = 42.5376898363° = 42°32'13″ = 0.742240893 rad
Angle ∠ C = γ = 94.9266203274° = 94°55'34″ = 1.65767747935 rad

Height: ha = 18.93298164317
Height: hb = 18.93298164317
Height: hc = 12.84552325787

Median: ma = 21.9660191256
Median: mb = 21.9660191256
Median: mc = 12.84552325787

Inradius: r = 5.44994926091
Circumradius: R = 14.05219059421

Vertex coordinates: A[28; 0] B[0; 0] C[14; 12.84552325787]
Centroid: CG[14; 4.28217441929]
Coordinates of the circumscribed circle: U[14; -1.20766733635]
Coordinates of the inscribed circle: I[14; 5.44994926091]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 137.4633101637° = 137°27'47″ = 0.742240893 rad
∠ B' = β' = 137.4633101637° = 137°27'47″ = 0.742240893 rad
∠ C' = γ' = 85.0743796726° = 85°4'26″ = 1.65767747935 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.