# 14 19 21 triangle

### Acute scalene triangle.

Sides: a = 14   b = 19   c = 21

Area: T = 129.8799845917
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 40.58988006955° = 40°35'20″ = 0.70884082116 rad
Angle ∠ B = β = 62.00554382677° = 62°20″ = 1.08221990519 rad
Angle ∠ C = γ = 77.40657610367° = 77°24'21″ = 1.35109853901 rad

Height: ha = 18.5432835131
Height: hb = 13.66331416754
Height: hc = 12.36218900873

Median: ma = 18.76216630393
Median: mb = 15.10879449297
Median: mc = 12.97111217711

Inradius: r = 4.80774017006
Circumradius: R = 10.7598872556

Vertex coordinates: A[21; 0] B[0; 0] C[6.57114285714; 12.36218900873]
Centroid: CG[9.19904761905; 4.12106300291]
Coordinates of the circumscribed circle: U[10.5; 2.34659195799]
Coordinates of the inscribed circle: I[8; 4.80774017006]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.4111199304° = 139°24'40″ = 0.70884082116 rad
∠ B' = β' = 117.9954561732° = 117°59'40″ = 1.08221990519 rad
∠ C' = γ' = 102.5944238963° = 102°35'39″ = 1.35109853901 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.