# 13 18 23 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 18   c = 23

Area: T = 116.6533332571
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 34.30111527568° = 34°18'4″ = 0.59986680528 rad
Angle ∠ B = β = 51.28771214574° = 51°17'14″ = 0.89551291333 rad
Angle ∠ C = γ = 94.41217257858° = 94°24'42″ = 1.64877954675 rad

Height: ha = 17.94766665494
Height: hb = 12.96114813968
Height: hc = 10.14437680497

Median: ma = 19.60222957839
Median: mb = 16.37107055437
Median: mc = 10.68987791632

Inradius: r = 4.32204937989
Circumradius: R = 11.53441754097

Vertex coordinates: A[23; 0] B[0; 0] C[8.13304347826; 10.14437680497]
Centroid: CG[10.37768115942; 3.38112560166]
Coordinates of the circumscribed circle: U[11.5; -0.88772442623]
Coordinates of the inscribed circle: I[9; 4.32204937989]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 145.6998847243° = 145°41'56″ = 0.59986680528 rad
∠ B' = β' = 128.7132878543° = 128°42'46″ = 0.89551291333 rad
∠ C' = γ' = 85.58882742142° = 85°35'18″ = 1.64877954675 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.