# 12 26 26 triangle

### Acute isosceles triangle.

Sides: a = 12   b = 26   c = 26

Area: T = 151.7899327688
Perimeter: p = 64
Semiperimeter: s = 32

Angle ∠ A = α = 26.68547275942° = 26°41'5″ = 0.46657363565 rad
Angle ∠ B = β = 76.65876362029° = 76°39'28″ = 1.33879281485 rad
Angle ∠ C = γ = 76.65876362029° = 76°39'28″ = 1.33879281485 rad

Height: ha = 25.29882212813
Height: hb = 11.67661021299
Height: hc = 11.67661021299

Median: ma = 25.29882212813
Median: mb = 15.52441746963
Median: mc = 15.52441746963

Inradius: r = 4.74334164903
Circumradius: R = 13.36106231142

Vertex coordinates: A[26; 0] B[0; 0] C[2.76992307692; 11.67661021299]
Centroid: CG[9.59897435897; 3.89220340433]
Coordinates of the circumscribed circle: U[13; 3.08332207187]
Coordinates of the inscribed circle: I[6; 4.74334164903]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 153.3155272406° = 153°18'55″ = 0.46657363565 rad
∠ B' = β' = 103.3422363797° = 103°20'32″ = 1.33879281485 rad
∠ C' = γ' = 103.3422363797° = 103°20'32″ = 1.33879281485 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.