# 15 21 22 triangle

### Acute scalene triangle.

Sides: a = 15   b = 21   c = 22

Area: T = 150.78546146
Perimeter: p = 58
Semiperimeter: s = 29

Angle ∠ A = α = 40.74990543775° = 40°44'57″ = 0.7111205166 rad
Angle ∠ B = β = 66.04223927371° = 66°2'33″ = 1.15326571992 rad
Angle ∠ C = γ = 73.20985528854° = 73°12'31″ = 1.27877302885 rad

Height: ha = 20.105461528
Height: hb = 14.36604394857
Height: hc = 13.70876922363

Median: ma = 20.15656443707
Median: mb = 15.62884996081
Median: mc = 14.56602197786

Inradius: r = 5.1999469469
Circumradius: R = 11.49898990497

Vertex coordinates: A[22; 0] B[0; 0] C[6.09109090909; 13.70876922363]
Centroid: CG[9.36436363636; 4.56992307454]
Coordinates of the circumscribed circle: U[11; 3.31993041699]
Coordinates of the inscribed circle: I[8; 5.1999469469]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.2510945623° = 139°15'3″ = 0.7111205166 rad
∠ B' = β' = 113.9587607263° = 113°57'27″ = 1.15326571992 rad
∠ C' = γ' = 106.7911447115° = 106°47'29″ = 1.27877302885 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.