Triangle calculator SSS - result

Please enter the triangle sides:

Acute scalene triangle.

Sides: a = 21   b = 23   c = 28

Area: T = 236.9811011898
Perimeter: p = 72
Semiperimeter: s = 36

Angle ∠ A = α = 47.38988944466° = 47°23'20″ = 0.8277092237 rad
Angle ∠ B = β = 53.71325429149° = 53°42'45″ = 0.93774607235 rad
Angle ∠ C = γ = 78.89985626385° = 78°53'55″ = 1.37770396931 rad

Height: ha = 22.57696201807
Height: hb = 20.60770445128
Height: hc = 16.92772151355

Median: ma = 23.3721991785
Median: mb = 21.91546070008
Median: mc = 17

Inradius: r = 6.5832805886
Circumradius: R = 14.26769658338

Vertex coordinates: A[28; 0] B[0; 0] C[12.42985714286; 16.92772151355]
Centroid: CG[13.47661904762; 5.64224050452]
Coordinates of the circumscribed circle: U[14; 2.74770555332]
Coordinates of the inscribed circle: I[13; 6.5832805886]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 132.6111105553° = 132°36'40″ = 0.8277092237 rad
∠ B' = β' = 126.2877457085° = 126°17'15″ = 0.93774607235 rad
∠ C' = γ' = 101.1011437362° = 101°6'5″ = 1.37770396931 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     