# 15 17 26 triangle

### Obtuse scalene triangle.

Sides: a = 15   b = 17   c = 26

Area: T = 120.8976650078
Perimeter: p = 58
Semiperimeter: s = 29

Angle ∠ A = α = 33.16444315181° = 33°9'52″ = 0.57988285245 rad
Angle ∠ B = β = 38.31548799765° = 38°18'54″ = 0.66987208081 rad
Angle ∠ C = γ = 108.5210688505° = 108°31'14″ = 1.8944043321 rad

Height: ha = 16.12195533437
Height: hb = 14.22331353033
Height: hc = 9.32997423137

Median: ma = 20.64658228221
Median: mb = 19.44986503388
Median: mc = 9.38108315196

Inradius: r = 4.16988500027
Circumradius: R = 13.71100573005

Vertex coordinates: A[26; 0] B[0; 0] C[11.76992307692; 9.32997423137]
Centroid: CG[12.59897435897; 3.10999141046]
Coordinates of the circumscribed circle: U[13; -4.35549593778]
Coordinates of the inscribed circle: I[12; 4.16988500027]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 146.8365568482° = 146°50'8″ = 0.57988285245 rad
∠ B' = β' = 141.6855120024° = 141°41'6″ = 0.66987208081 rad
∠ C' = γ' = 71.47993114946° = 71°28'46″ = 1.8944043321 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.