# Triangle calculator SSS - result

Please enter the triangle sides:

### Acute isosceles triangle.

Sides: a = 16   b = 16   c = 21

Area: T = 126.763331291
Perimeter: p = 53
Semiperimeter: s = 26.5

Angle ∠ A = α = 48.98655003343° = 48°59'8″ = 0.85549582666 rad
Angle ∠ B = β = 48.98655003343° = 48°59'8″ = 0.85549582666 rad
Angle ∠ C = γ = 82.02989993315° = 82°1'44″ = 1.43216761205 rad

Height: ha = 15.84554141138
Height: hb = 15.84554141138
Height: hc = 12.07326964676

Median: ma = 16.86771277934
Median: mb = 16.86771277934
Median: mc = 12.07326964676

Inradius: r = 4.78435212419
Circumradius: R = 10.6022436692

Vertex coordinates: A[21; 0] B[0; 0] C[10.5; 12.07326964676]
Centroid: CG[10.5; 4.02442321559]
Coordinates of the circumscribed circle: U[10.5; 1.47702597756]
Coordinates of the inscribed circle: I[10.5; 4.78435212419]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 131.0144499666° = 131°52″ = 0.85549582666 rad
∠ B' = β' = 131.0144499666° = 131°52″ = 0.85549582666 rad
∠ C' = γ' = 97.97110006685° = 97°58'16″ = 1.43216761205 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   