# 40 40 56.57 triangle

### Obtuse isosceles triangle.

Sides: a = 40   b = 40   c = 56.57

Area: T = 8009.999998938
Perimeter: p = 136.57
Semiperimeter: s = 68.285

Angle ∠ A = α = 44.99985237384° = 44°59'55″ = 0.78553723978 rad
Angle ∠ B = β = 44.99985237384° = 44°59'55″ = 0.78553723978 rad
Angle ∠ C = γ = 90.00329525231° = 90°11″ = 1.5710847858 rad

Height: ha = 409.9999999469
Height: hb = 409.9999999469
Height: hc = 28.28435424761

Median: ma = 44.72222813595
Median: mb = 44.72222813595
Median: mc = 28.28435424761

Inradius: r = 11.71656037041
Circumradius: R = 28.28550000376

Vertex coordinates: A[56.57; 0] B[0; 0] C[28.285; 28.28435424761]
Centroid: CG[28.285; 9.4287847492]
Coordinates of the circumscribed circle: U[28.285; -0.00114575614]
Coordinates of the inscribed circle: I[28.285; 11.71656037041]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 135.0011476262° = 135°5″ = 0.78553723978 rad
∠ B' = β' = 135.0011476262° = 135°5″ = 0.78553723978 rad
∠ C' = γ' = 89.99770474769° = 89°59'49″ = 1.5710847858 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    