Triangle calculator

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

Obtuse scalene triangle.

Sides: a = 11.2   b = 6.5   c = 8.3

Area: T = 26.73770529416
Perimeter: p = 26
Semiperimeter: s = 13

Angle ∠ A = α = 97.61658228711° = 97°36'57″ = 1.70437175111 rad
Angle ∠ B = β = 35.11662871715° = 35°6'59″ = 0.61328948322 rad
Angle ∠ C = γ = 47.26878899574° = 47°16'4″ = 0.82549803102 rad

Height: ha = 4.77444737396
Height: hb = 8.22767855205
Height: hc = 6.44326633594

Median: ma = 4.92203658401
Median: mb = 9.30660464215
Median: mc = 8.16222607162

Inradius: r = 2.05766963801
Circumradius: R = 5.65498373374

Vertex coordinates: A[8.3; 0] B[0; 0] C[9.16114457831; 6.44326633594]
Centroid: CG[5.82204819277; 2.14875544531]
Coordinates of the circumscribed circle: U[4.15; 3.83438181932]
Coordinates of the inscribed circle: I[6.5; 2.05766963801]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 82.38441771289° = 82°23'3″ = 1.70437175111 rad
∠ B' = β' = 144.8843712829° = 144°53'1″ = 0.61328948322 rad
∠ C' = γ' = 132.7322110043° = 132°43'56″ = 0.82549803102 rad

How did we calculate this triangle?

1. Input data entered: side a, b and perimeter p. 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. 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     