# 17 20 29 triangle

### Obtuse scalene triangle.

Sides: a = 17   b = 20   c = 29

Area: T = 165.6998521418
Perimeter: p = 66
Semiperimeter: s = 33

Angle ∠ A = α = 34.84661094173° = 34°50'46″ = 0.60881793408 rad
Angle ∠ B = β = 42.23774732352° = 42°14'15″ = 0.73771829757 rad
Angle ∠ C = γ = 102.9166417347° = 102°54'59″ = 1.79662303371 rad

Height: ha = 19.49439436962
Height: hb = 16.57698521418
Height: hc = 11.42774842357

Median: ma = 23.41547389479
Median: mb = 21.56438586528
Median: mc = 11.58766302263

Inradius: r = 5.02111673157
Circumradius: R = 14.87664151841

Vertex coordinates: A[29; 0] B[0; 0] C[12.58662068966; 11.42774842357]
Centroid: CG[13.86220689655; 3.80991614119]
Coordinates of the circumscribed circle: U[14.5; -3.32553163353]
Coordinates of the inscribed circle: I[13; 5.02111673157]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 145.1543890583° = 145°9'14″ = 0.60881793408 rad
∠ B' = β' = 137.7632526765° = 137°45'45″ = 0.73771829757 rad
∠ C' = γ' = 77.08435826525° = 77°5'1″ = 1.79662303371 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    