# 19 23 26 triangle

### Acute scalene triangle.

Sides: a = 19   b = 23   c = 26

Area: T = 211.849900283
Perimeter: p = 68
Semiperimeter: s = 34

Angle ∠ A = α = 45.11550392061° = 45°6'54″ = 0.78774059763 rad
Angle ∠ B = β = 59.05880045405° = 59°3'29″ = 1.03107566289 rad
Angle ∠ C = γ = 75.82769562534° = 75°49'37″ = 1.32334300484 rad

Height: ha = 22.32998950347
Height: hb = 18.422165242
Height: hc = 16.29660771408

Median: ma = 22.63329405955
Median: mb = 19.6533244007
Median: mc = 16.61332477258

Inradius: r = 6.23108530244
Circumradius: R = 13.40881348605

Vertex coordinates: A[26; 0] B[0; 0] C[9.76992307692; 16.29660771408]
Centroid: CG[11.92330769231; 5.43220257136]
Coordinates of the circumscribed circle: U[13; 3.28329986958]
Coordinates of the inscribed circle: I[11; 6.23108530244]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 134.8854960794° = 134°53'6″ = 0.78774059763 rad
∠ B' = β' = 120.9421995459° = 120°56'31″ = 1.03107566289 rad
∠ C' = γ' = 104.1733043747° = 104°10'23″ = 1.32334300484 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    