# 13 19 26 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 19   c = 26

Area: T = 117.983304963
Perimeter: p = 58
Semiperimeter: s = 29

Angle ∠ A = α = 28.53329559873° = 28°31'59″ = 0.49879940273 rad
Angle ∠ B = β = 44.27767297027° = 44°16'36″ = 0.77327747153 rad
Angle ∠ C = γ = 107.199031431° = 107°11'25″ = 1.8710823911 rad

Height: ha = 18.15112384046
Height: hb = 12.41992683821
Height: hc = 9.07656192023

Median: ma = 21.82331528428
Median: mb = 18.22877261336
Median: mc = 9.79879589711

Inradius: r = 4.06883810217
Circumradius: R = 13.60878869383

Vertex coordinates: A[26; 0] B[0; 0] C[9.30876923077; 9.07656192023]
Centroid: CG[11.76992307692; 3.02552064008]
Coordinates of the circumscribed circle: U[13; -4.02217641559]
Coordinates of the inscribed circle: I[10; 4.06883810217]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.4677044013° = 151°28'1″ = 0.49879940273 rad
∠ B' = β' = 135.7233270297° = 135°43'24″ = 0.77327747153 rad
∠ C' = γ' = 72.81096856901° = 72°48'35″ = 1.8710823911 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.