Triangle calculator SSS - result

Please enter the triangle sides:

Acute isosceles triangle.

Sides: a = 7   b = 20   c = 20

Area: T = 68.92197903363
Perimeter: p = 47
Semiperimeter: s = 23.5

Angle ∠ A = α = 20.15773162156° = 20°9'26″ = 0.35218115363 rad
Angle ∠ B = β = 79.92113418922° = 79°55'17″ = 1.39548905586 rad
Angle ∠ C = γ = 79.92113418922° = 79°55'17″ = 1.39548905586 rad

Height: ha = 19.69113686675
Height: hb = 6.89219790336
Height: hc = 6.89219790336

Median: ma = 19.69113686675
Median: mb = 11.15879568022
Median: mc = 11.15879568022

Inradius: r = 2.93327570356
Circumradius: R = 10.15767343224

Vertex coordinates: A[20; 0] B[0; 0] C[1.225; 6.89219790336]
Centroid: CG[7.075; 2.29773263445]
Coordinates of the circumscribed circle: U[10; 1.77774285064]
Coordinates of the inscribed circle: I[3.5; 2.93327570356]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 159.8432683784° = 159°50'34″ = 0.35218115363 rad
∠ B' = β' = 100.0798658108° = 100°4'43″ = 1.39548905586 rad
∠ C' = γ' = 100.0798658108° = 100°4'43″ = 1.39548905586 rad

How did we calculate this triangle?

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     