# 18 19 26 triangle

### Acute scalene triangle.

Sides: a = 18   b = 19   c = 26

Area: T = 170.9855196728
Perimeter: p = 63
Semiperimeter: s = 31.5

Angle ∠ A = α = 43.80883029818° = 43°48'30″ = 0.76545991267 rad
Angle ∠ B = β = 46.94656106092° = 46°56'44″ = 0.81993554745 rad
Angle ∠ C = γ = 89.2466086409° = 89°14'46″ = 1.55876380524 rad

Height: ha = 18.9988355192
Height: hb = 17.99884417608
Height: hc = 13.15327074406

Median: ma = 20.91765006634
Median: mb = 20.242228248
Median: mc = 13.17219398723

Inradius: r = 5.42881014834
Circumradius: R = 13.00111254924

Vertex coordinates: A[26; 0] B[0; 0] C[12.28884615385; 13.15327074406]
Centroid: CG[12.76328205128; 4.38442358135]
Coordinates of the circumscribed circle: U[13; 0.17110674407]
Coordinates of the inscribed circle: I[12.5; 5.42881014834]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 136.1921697018° = 136°11'30″ = 0.76545991267 rad
∠ B' = β' = 133.0544389391° = 133°3'16″ = 0.81993554745 rad
∠ C' = γ' = 90.7543913591° = 90°45'14″ = 1.55876380524 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.