# 17 21 29 triangle

### Obtuse scalene triangle.

Sides: a = 17   b = 21   c = 29

Area: T = 176.3329769183
Perimeter: p = 67
Semiperimeter: s = 33.5

Angle ∠ A = α = 35.38658397649° = 35°23'9″ = 0.61875994125 rad
Angle ∠ B = β = 45.67105577996° = 45°40'14″ = 0.79771016048 rad
Angle ∠ C = γ = 98.94436024355° = 98°56'37″ = 1.72768916363 rad

Height: ha = 20.74546787274
Height: hb = 16.79333113507
Height: hc = 12.16106737367

Median: ma = 23.84884800354
Median: mb = 21.32548681121
Median: mc = 12.44398553046

Inradius: r = 5.26435751995
Circumradius: R = 14.67884630411

Vertex coordinates: A[29; 0] B[0; 0] C[11.87993103448; 12.16106737367]
Centroid: CG[13.62664367816; 4.05435579122]
Coordinates of the circumscribed circle: U[14.5; -2.2821945935]
Coordinates of the inscribed circle: I[12.5; 5.26435751995]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 144.6144160235° = 144°36'51″ = 0.61875994125 rad
∠ B' = β' = 134.32994422° = 134°19'46″ = 0.79771016048 rad
∠ C' = γ' = 81.05663975645° = 81°3'23″ = 1.72768916363 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    