# Triangle calculator

Please enter what you know about the triangle:
You have entered side a, b and angle γ.

### Acute isosceles triangle.

Sides: a = 1.5   b = 1.5   c = 1.5

Area: T = 0.97442785793
Perimeter: p = 4.5
Semiperimeter: s = 2.25

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

Height: ha = 1.29990381057
Height: hb = 1.29990381057
Height: hc = 1.29990381057

Median: ma = 1.29990381057
Median: mb = 1.29990381057
Median: mc = 1.29990381057

Inradius: r = 0.43330127019
Circumradius: R = 0.86660254038

Vertex coordinates: A[1.5; 0] B[0; 0] C[0.75; 1.29990381057]
Centroid: CG[0.75; 0.43330127019]
Coordinates of the circumscribed circle: U[0.75; 0.43330127019]
Coordinates of the inscribed circle: I[0.75; 0.43330127019]

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?

### 1. Input data entered: side a, b and angle γ. ### 2. Calculation of the third side c of the triangle using a Law of Cosines 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. ### 3. The triangle circumference is the sum of the lengths of its three sides ### 4. Semiperimeter of the triangle ### 5. The triangle area using Heron's formula ### 6. Calculate the heights of the triangle from its area. ### 7. Calculation of the inner angles of the triangle using a Law of Cosines    