# 19 28 29 triangle

### Acute scalene triangle.

Sides: a = 19   b = 28   c = 29

Area: T = 254.9121749435
Perimeter: p = 76
Semiperimeter: s = 38

Angle ∠ A = α = 38.89325199738° = 38°53'33″ = 0.67988025279 rad
Angle ∠ B = β = 67.70990296252° = 67°42'33″ = 1.18217455003 rad
Angle ∠ C = γ = 73.3988450401° = 73°23'54″ = 1.28110446254 rad

Height: ha = 26.833281573
Height: hb = 18.20879821025
Height: hc = 17.58801206507

Median: ma = 26.87547093008
Median: mb = 20.12546117975
Median: mc = 19.03328663107

Inradius: r = 6.70882039325
Circumradius: R = 15.13107266477

Vertex coordinates: A[29; 0] B[0; 0] C[7.20768965517; 17.58801206507]
Centroid: CG[12.06989655172; 5.86600402169]
Coordinates of the circumscribed circle: U[14.5; 4.32330647565]
Coordinates of the inscribed circle: I[10; 6.70882039325]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 141.1077480026° = 141°6'27″ = 0.67988025279 rad
∠ B' = β' = 112.2910970375° = 112°17'27″ = 1.18217455003 rad
∠ C' = γ' = 106.6021549599° = 106°36'6″ = 1.28110446254 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    