3 13 13 triangle

Acute isosceles triangle.

Sides: a = 3   b = 13   c = 13

Area: T = 19.37697573552
Perimeter: p = 29
Semiperimeter: s = 14.5

Angle ∠ A = α = 13.25216191296° = 13°15'6″ = 0.2311284385 rad
Angle ∠ B = β = 83.37441904352° = 83°22'27″ = 1.45551541343 rad
Angle ∠ C = γ = 83.37441904352° = 83°22'27″ = 1.45551541343 rad

Height: ha = 12.91331715701
Height: hb = 2.987996267
Height: hc = 2.987996267

Median: ma = 12.91331715701
Median: mb = 6.83773971656
Median: mc = 6.83773971656

Vertex coordinates: A[13; 0] B[0; 0] C[0.34661538462; 2.987996267]
Centroid: CG[4.44987179487; 0.993332089]
Coordinates of the circumscribed circle: U[6.5; 0.75550430153]
Coordinates of the inscribed circle: I[1.5; 1.33658453348]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 166.748838087° = 166°44'54″ = 0.2311284385 rad
∠ B' = β' = 96.62658095648° = 96°37'33″ = 1.45551541343 rad
∠ C' = γ' = 96.62658095648° = 96°37'33″ = 1.45551541343 rad

How did we calculate this triangle?

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. 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    