# 13 19 19 triangle

### Acute isosceles triangle.

Sides: a = 13   b = 19   c = 19

Area: T = 116.0488211964
Perimeter: p = 51
Semiperimeter: s = 25.5

Angle ∠ A = α = 40.01103801763° = 40°37″ = 0.69883128691 rad
Angle ∠ B = β = 69.99548099118° = 69°59'41″ = 1.22216398923 rad
Angle ∠ C = γ = 69.99548099118° = 69°59'41″ = 1.22216398923 rad

Height: ha = 17.85435710714
Height: hb = 12.21656012593
Height: hc = 12.21656012593

Median: ma = 17.85435710714
Median: mb = 13.21993040664
Median: mc = 13.21993040664

Inradius: r = 4.55109102731
Circumradius: R = 10.11100222067

Vertex coordinates: A[19; 0] B[0; 0] C[4.44773684211; 12.21656012593]
Centroid: CG[7.81657894737; 4.07218670864]
Coordinates of the circumscribed circle: U[9.5; 3.45986918075]
Coordinates of the inscribed circle: I[6.5; 4.55109102731]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.9989619824° = 139°59'23″ = 0.69883128691 rad
∠ B' = β' = 110.0055190088° = 110°19″ = 1.22216398923 rad
∠ C' = γ' = 110.0055190088° = 110°19″ = 1.22216398923 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 ### 6. Inradius ### 7. Circumradius ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.