10 20 20 triangle

Acute isosceles triangle.

Sides: a = 10   b = 20   c = 20

Area: T = 96.82545836552
Perimeter: p = 50
Semiperimeter: s = 25

Angle ∠ A = α = 28.95550243719° = 28°57'18″ = 0.50553605103 rad
Angle ∠ B = β = 75.52224878141° = 75°31'21″ = 1.31881160717 rad
Angle ∠ C = γ = 75.52224878141° = 75°31'21″ = 1.31881160717 rad

Height: ha = 19.3654916731
Height: hb = 9.68224583655
Height: hc = 9.68224583655

Median: ma = 19.3654916731
Median: mb = 12.24774487139
Median: mc = 12.24774487139

Vertex coordinates: A[20; 0] B[0; 0] C[2.5; 9.68224583655]
Centroid: CG[7.5; 3.22774861218]
Coordinates of the circumscribed circle: U[10; 2.58219888975]
Coordinates of the inscribed circle: I[5; 3.87329833462]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.0454975628° = 151°2'42″ = 0.50553605103 rad
∠ B' = β' = 104.4787512186° = 104°28'39″ = 1.31881160717 rad
∠ C' = γ' = 104.4787512186° = 104°28'39″ = 1.31881160717 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    