# Isosceles triangle calculator (a,b,c)

Please enter two properties of the isosceles triangle

Use symbols: a, b, h, T, p, A, B, C, r, R

You have entered side a, b and c.

### Equilateral triangle.

Sides: a = 75   b = 75   c = 75

Area: T = 2435.696644814
Perimeter: p = 225
Semiperimeter: s = 112.5

Angle ∠ A = α = 60° = 1.04771975512 rad
Angle ∠ B = β = 60° = 1.04771975512 rad
Angle ∠ C = γ = 60° = 1.04771975512 rad

Height: ha = 64.95219052838
Height: hb = 64.95219052838
Height: hc = 64.95219052838

Median: ma = 64.95219052838
Median: mb = 64.95219052838
Median: mc = 64.95219052838

Vertex coordinates: A[75; 0] B[0; 0] C[37.5; 64.95219052838]
Centroid: CG[37.5; 21.65106350946]
Coordinates of the circumscribed circle: U[37.5; 21.65106350946]
Coordinates of the inscribed circle: I[37.5; 21.65106350946]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 120° = 1.04771975512 rad
∠ B' = β' = 120° = 1.04771975512 rad
∠ C' = γ' = 120° = 1.04771975512 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.