# 15 18 23 triangle

### Acute scalene triangle.

Sides: a = 15   b = 18   c = 23

Area: T = 134.9077375632
Perimeter: p = 56
Semiperimeter: s = 28

Angle ∠ A = α = 40.67218958023° = 40°40'19″ = 0.71098584948 rad
Angle ∠ B = β = 51.45106555599° = 51°27'2″ = 0.89879833418 rad
Angle ∠ C = γ = 87.87774486379° = 87°52'39″ = 1.5343750817 rad

Height: ha = 17.98876500843
Height: hb = 14.99897084036
Height: hc = 11.73110761419

Median: ma = 19.24218814049
Median: mb = 17.20546505341
Median: mc = 11.92768604419

Inradius: r = 4.81881205583
Circumradius: R = 11.50878956412

Vertex coordinates: A[23; 0] B[0; 0] C[9.3487826087; 11.73110761419]
Centroid: CG[10.78326086957; 3.9110358714]
Coordinates of the circumscribed circle: U[11.5; 0.42662183571]
Coordinates of the inscribed circle: I[10; 4.81881205583]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.3288104198° = 139°19'41″ = 0.71098584948 rad
∠ B' = β' = 128.549934444° = 128°32'58″ = 0.89879833418 rad
∠ C' = γ' = 92.12325513621° = 92°7'21″ = 1.5343750817 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.