# 8 19 20 triangle

### Acute scalene triangle.

Sides: a = 8   b = 19   c = 20

Area: T = 75.74325738934
Perimeter: p = 47
Semiperimeter: s = 23.5

Angle ∠ A = α = 23.49435060326° = 23°29'37″ = 0.41100390331 rad
Angle ∠ B = β = 71.22436450997° = 71°13'25″ = 1.24330871123 rad
Angle ∠ C = γ = 85.28328488678° = 85°16'58″ = 1.48884665082 rad

Height: ha = 18.93656434734
Height: hb = 7.97329025151
Height: hc = 7.57442573893

Median: ma = 19.0921883092
Median: mb = 11.90658808998
Median: mc = 10.60766017178

Inradius: r = 3.22330882508
Circumradius: R = 10.03439869763

Vertex coordinates: A[20; 0] B[0; 0] C[2.575; 7.57442573893]
Centroid: CG[7.525; 2.52547524631]
Coordinates of the circumscribed circle: U[10; 0.82551634027]
Coordinates of the inscribed circle: I[4.5; 3.22330882508]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 156.5066493967° = 156°30'23″ = 0.41100390331 rad
∠ B' = β' = 108.77663549° = 108°46'35″ = 1.24330871123 rad
∠ C' = γ' = 94.71771511322° = 94°43'2″ = 1.48884665082 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.