Triangle calculator

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

Obtuse isosceles triangle.

Sides: a = 6.5   b = 6.5   c = 10.5

Area: T = 20.12202440032
Perimeter: p = 23.5
Semiperimeter: s = 11.75

Angle ∠ A = α = 36.12989274719° = 36°7'44″ = 0.63105687396 rad
Angle ∠ B = β = 36.12989274719° = 36°7'44″ = 0.63105687396 rad
Angle ∠ C = γ = 107.7422145056° = 107°44'32″ = 1.88804551744 rad

Height: ha = 6.19108443087
Height: hb = 6.19108443087
Height: hc = 3.83224274292

Median: ma = 8.10547825387
Median: mb = 8.10547825387
Median: mc = 3.83224274292

Inradius: r = 1.71223611918
Circumradius: R = 5.51221722173

Vertex coordinates: A[10.5; 0] B[0; 0] C[5.25; 3.83224274292]
Centroid: CG[5.25; 1.27774758097]
Coordinates of the circumscribed circle: U[5.25; -1.68797447881]
Coordinates of the inscribed circle: I[5.25; 1.71223611918]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 143.8711072528° = 143°52'16″ = 0.63105687396 rad
∠ B' = β' = 143.8711072528° = 143°52'16″ = 0.63105687396 rad
∠ C' = γ' = 72.25878549439° = 72°15'28″ = 1.88804551744 rad

How did we calculate this triangle?

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