# Isosceles triangle calculator (b)

Please enter two properties of the isosceles triangle

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

You have entered side b and angle γ.

### Obtuse isosceles triangle.

Sides: a = 106.4187777248   b = 106.4187777248   c = 200

Area: T = 3639.702234266
Perimeter: p = 412.8365554495
Semiperimeter: s = 206.4187777248

Angle ∠ A = α = 20° = 0.34990658504 rad
Angle ∠ B = β = 20° = 0.34990658504 rad
Angle ∠ C = γ = 140° = 2.44334609528 rad

Height: ha = 68.40440286651
Height: hb = 68.40440286651
Height: hc = 36.39770234266

Median: ma = 151.1099920015
Median: mb = 151.1099920015
Median: mc = 36.39770234266

Vertex coordinates: A[200; 0] B[0; 0] C[100; 36.39770234266]
Centroid: CG[100; 12.13223411422]
Coordinates of the circumscribed circle: U[100; -119.1755359259]
Coordinates of the inscribed circle: I[100; 17.63326980708]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 160° = 0.34990658504 rad
∠ B' = β' = 160° = 0.34990658504 rad
∠ C' = γ' = 40° = 2.44334609528 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    