# 9 21 22 triangle

### Acute scalene triangle.

Sides: a = 9   b = 21   c = 22

Area: T = 94.02112741883
Perimeter: p = 52
Semiperimeter: s = 26

Angle ∠ A = α = 24.0187678915° = 24°1'4″ = 0.41991875758 rad
Angle ∠ B = β = 71.75219603276° = 71°45'7″ = 1.25223079525 rad
Angle ∠ C = γ = 84.23303607573° = 84°13'49″ = 1.47700971254 rad

Height: ha = 20.89436164863
Height: hb = 8.95444070656
Height: hc = 8.54773885626

Median: ma = 21.03297408448
Median: mb = 13.12444047484
Median: mc = 11.83221595662

Inradius: r = 3.61662028534
Circumradius: R = 11.05660084297

Vertex coordinates: A[22; 0] B[0; 0] C[2.81881818182; 8.54773885626]
Centroid: CG[8.27327272727; 2.84991295209]
Coordinates of the circumscribed circle: U[11; 1.11114505829]
Coordinates of the inscribed circle: I[5; 3.61662028534]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 155.9822321085° = 155°58'56″ = 0.41991875758 rad
∠ B' = β' = 108.2488039672° = 108°14'53″ = 1.25223079525 rad
∠ C' = γ' = 95.77696392427° = 95°46'11″ = 1.47700971254 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.