# 17 26 26 triangle

### Acute isosceles triangle.

Sides: a = 17   b = 26   c = 26

Area: T = 208.856626038
Perimeter: p = 69
Semiperimeter: s = 34.5

Angle ∠ A = α = 38.16442496072° = 38°9'51″ = 0.66660918122 rad
Angle ∠ B = β = 70.91878751964° = 70°55'4″ = 1.23877504207 rad
Angle ∠ C = γ = 70.91878751964° = 70°55'4″ = 1.23877504207 rad

Height: ha = 24.57113247506
Height: hb = 16.06658661831
Height: hc = 16.06658661831

Median: ma = 24.57113247506
Median: mb = 17.70659312096
Median: mc = 17.70659312096

Inradius: r = 6.05438046487
Circumradius: R = 13.75658720757

Vertex coordinates: A[26; 0] B[0; 0] C[5.55876923077; 16.06658661831]
Centroid: CG[10.51992307692; 5.35552887277]
Coordinates of the circumscribed circle: U[13; 4.49771120247]
Coordinates of the inscribed circle: I[8.5; 6.05438046487]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 141.8365750393° = 141°50'9″ = 0.66660918122 rad
∠ B' = β' = 109.0822124804° = 109°4'56″ = 1.23877504207 rad
∠ C' = γ' = 109.0822124804° = 109°4'56″ = 1.23877504207 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.