# 10 18 26 triangle

### Obtuse scalene triangle.

Sides: a = 10   b = 18   c = 26

Area: T = 64.27328558569
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 15.94223686056° = 15°56'33″ = 0.27882468227 rad
Angle ∠ B = β = 29.63106273936° = 29°37'50″ = 0.51771520074 rad
Angle ∠ C = γ = 134.4277004001° = 134°25'37″ = 2.34661938234 rad

Height: ha = 12.85545711714
Height: hb = 7.14114284285
Height: hc = 4.94440658351

Median: ma = 21.79444947177
Median: mb = 17.52114154679
Median: mc = 6.55774385243

Inradius: r = 2.38804761428
Circumradius: R = 18.20436410924

Vertex coordinates: A[26; 0] B[0; 0] C[8.69223076923; 4.94440658351]
Centroid: CG[11.56441025641; 1.6488021945]
Coordinates of the circumscribed circle: U[13; -12.74325487647]
Coordinates of the inscribed circle: I[9; 2.38804761428]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 164.0587631394° = 164°3'27″ = 0.27882468227 rad
∠ B' = β' = 150.3699372606° = 150°22'10″ = 0.51771520074 rad
∠ C' = γ' = 45.57329959992° = 45°34'23″ = 2.34661938234 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.