Triangle calculator SSS - result

Please enter the triangle sides:

Acute isosceles triangle.

Sides: a = 18   b = 26   c = 26

Area: T = 219.5343596518
Perimeter: p = 70
Semiperimeter: s = 35

Angle ∠ A = α = 40.50444934844° = 40°30'16″ = 0.70769367732 rad
Angle ∠ B = β = 69.74877532578° = 69°44'52″ = 1.21773279402 rad
Angle ∠ C = γ = 69.74877532578° = 69°44'52″ = 1.21773279402 rad

Height: ha = 24.39326218353
Height: hb = 16.88771997321
Height: hc = 16.88771997321

Median: ma = 24.39326218353
Median: mb = 18.19334053987
Median: mc = 18.19334053987

Inradius: r = 6.27223884719
Circumradius: R = 13.85766490426

Vertex coordinates: A[26; 0] B[0; 0] C[6.23107692308; 16.88771997321]
Centroid: CG[10.74435897436; 5.62990665774]
Coordinates of the circumscribed circle: U[13; 4.79765323609]
Coordinates of the inscribed circle: I[9; 6.27223884719]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.4965506516° = 139°29'44″ = 0.70769367732 rad
∠ B' = β' = 110.2522246742° = 110°15'8″ = 1.21773279402 rad
∠ C' = γ' = 110.2522246742° = 110°15'8″ = 1.21773279402 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     