# 9 21 29 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 21   c = 29

Area: T = 50.69770166775
Perimeter: p = 59
Semiperimeter: s = 29.5

Angle ∠ A = α = 9.58439574325° = 9°35'2″ = 0.16772716126 rad
Angle ∠ B = β = 22.8660133051° = 22°51'36″ = 0.39989845892 rad
Angle ∠ C = γ = 147.5565909516° = 147°33'21″ = 2.57553364518 rad

Height: ha = 11.26660037061
Height: hb = 4.82882873026
Height: hc = 3.49663459778

Median: ma = 24.91548550066
Median: mb = 18.72883208003
Median: mc = 7.12439034244

Inradius: r = 1.71985429382
Circumradius: R = 27.0288217631

Vertex coordinates: A[29; 0] B[0; 0] C[8.29331034483; 3.49663459778]
Centroid: CG[12.43110344828; 1.16554486593]
Coordinates of the circumscribed circle: U[14.5; -22.81095275774]
Coordinates of the inscribed circle: I[8.5; 1.71985429382]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 170.4166042567° = 170°24'58″ = 0.16772716126 rad
∠ B' = β' = 157.1439866949° = 157°8'24″ = 0.39989845892 rad
∠ C' = γ' = 32.44440904835° = 32°26'39″ = 2.57553364518 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    