# 7 21 22 triangle

### Acute scalene triangle.

Sides: a = 7   b = 21   c = 22

Area: T = 73.48546922835
Perimeter: p = 50
Semiperimeter: s = 25

Angle ∠ A = α = 18.54989996134° = 18°32'56″ = 0.32437411162 rad
Angle ∠ B = β = 72.62203831922° = 72°37'13″ = 1.26774647908 rad
Angle ∠ C = γ = 88.83106171944° = 88°49'50″ = 1.55503867466 rad

Height: ha = 20.99656263667
Height: hb = 6.99985421222
Height: hc = 6.68804265712

Median: ma = 21.21990951739
Median: mb = 12.5
Median: mc = 11.13655287257

Inradius: r = 2.93993876913
Circumradius: R = 11.0022291428

Vertex coordinates: A[22; 0] B[0; 0] C[2.09109090909; 6.68804265712]
Centroid: CG[8.03303030303; 2.22768088571]
Coordinates of the circumscribed circle: U[11; 0.22545365598]
Coordinates of the inscribed circle: I[4; 2.93993876913]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.4511000387° = 161°27'4″ = 0.32437411162 rad
∠ B' = β' = 107.3879616808° = 107°22'47″ = 1.26774647908 rad
∠ C' = γ' = 91.16993828056° = 91°10'10″ = 1.55503867466 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.