# 3 21 23 triangle

### Obtuse scalene triangle.

Sides: a = 3   b = 21   c = 23

Area: T = 24.543950896
Perimeter: p = 47
Semiperimeter: s = 23.5

Angle ∠ A = α = 5.83220544803° = 5°49'55″ = 0.10217885528 rad
Angle ∠ B = β = 45.34399797869° = 45°20'24″ = 0.79113319301 rad
Angle ∠ C = γ = 128.8287965733° = 128°49'41″ = 2.24884721707 rad

Height: ha = 16.365967264
Height: hb = 2.33770960914
Height: hc = 2.13438703444

Median: ma = 21.97215725427
Median: mb = 12.65996031684
Median: mc = 9.63106801421

Inradius: r = 1.04442344238
Circumradius: R = 14.76219090745

Vertex coordinates: A[23; 0] B[0; 0] C[2.10986956522; 2.13438703444]
Centroid: CG[8.37695652174; 0.71112901148]
Coordinates of the circumscribed circle: U[11.5; -9.25554826737]
Coordinates of the inscribed circle: I[2.5; 1.04442344238]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 174.168794552° = 174°10'5″ = 0.10217885528 rad
∠ B' = β' = 134.6660020213° = 134°39'36″ = 0.79113319301 rad
∠ C' = γ' = 51.17220342672° = 51°10'19″ = 2.24884721707 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.