# 8 21 23 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 21   c = 23

Area: T = 83.78554402626
Perimeter: p = 52
Semiperimeter: s = 26

Angle ∠ A = α = 20.33001215246° = 20°18' = 0.35443039592 rad
Angle ∠ B = β = 65.60438347173° = 65°36'14″ = 1.14550029178 rad
Angle ∠ C = γ = 94.09660437582° = 94°5'46″ = 1.64222857767 rad

Height: ha = 20.94663600657
Height: hb = 7.98795657393
Height: hc = 7.28656904576

Median: ma = 21.65664078277
Median: mb = 13.6477344064
Median: mc = 10.96658560997

Inradius: r = 3.22325169332
Circumradius: R = 11.5299449472

Vertex coordinates: A[23; 0] B[0; 0] C[3.30443478261; 7.28656904576]
Centroid: CG[8.7688115942; 2.42985634859]
Coordinates of the circumscribed circle: U[11.5; -0.82435321051]
Coordinates of the inscribed circle: I[5; 3.22325169332]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 159.7699878475° = 159°42' = 0.35443039592 rad
∠ B' = β' = 114.3966165283° = 114°23'46″ = 1.14550029178 rad
∠ C' = γ' = 85.90439562418° = 85°54'14″ = 1.64222857767 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.