21 21 29 triangle
Acute isosceles triangle.
Sides: a = 21 b = 21 c = 29Area: T = 220.2621634199
Perimeter: p = 71
Semiperimeter: s = 35.5
Angle ∠ A = α = 46.33221847017° = 46°19'56″ = 0.80986491727 rad
Angle ∠ B = β = 46.33221847017° = 46°19'56″ = 0.80986491727 rad
Angle ∠ C = γ = 87.33656305966° = 87°20'8″ = 1.52442943082 rad
Height: ha = 20.97772984951
Height: hb = 20.97772984951
Height: hc = 15.1990457531
Median: ma = 23.0388012067
Median: mb = 23.0388012067
Median: mc = 15.1990457531
Inradius: r = 6.2054553076
Circumradius: R = 14.51656918118
Vertex coordinates: A[29; 0] B[0; 0] C[14.5; 15.1990457531]
Centroid: CG[14.5; 5.06334858437]
Coordinates of the circumscribed circle: U[14.5; 0.67547657191]
Coordinates of the inscribed circle: I[14.5; 6.2054553076]
Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 133.6687815298° = 133°40'4″ = 0.80986491727 rad
∠ B' = β' = 133.6687815298° = 133°40'4″ = 0.80986491727 rad
∠ C' = γ' = 92.66443694034° = 92°39'52″ = 1.52442943082 rad
Calculate another triangle
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
