# 9 26 26 triangle

### Acute isosceles triangle.

Sides: a = 9   b = 26   c = 26

Area: T = 115.2344272246
Perimeter: p = 61
Semiperimeter: s = 30.5

Angle ∠ A = α = 19.93435326005° = 19°56'1″ = 0.34879057754 rad
Angle ∠ B = β = 80.03332336998° = 80°2' = 1.39768434391 rad
Angle ∠ C = γ = 80.03332336998° = 80°2' = 1.39768434391 rad

Height: ha = 25.60876160546
Height: hb = 8.86441747881
Height: hc = 8.86441747881

Median: ma = 25.60876160546
Median: mb = 14.47441148261
Median: mc = 14.47441148261

Inradius: r = 3.77881728605
Circumradius: R = 13.19991982104

Vertex coordinates: A[26; 0] B[0; 0] C[1.55876923077; 8.86441747881]
Centroid: CG[9.18658974359; 2.95547249294]
Coordinates of the circumscribed circle: U[13; 2.28444766133]
Coordinates of the inscribed circle: I[4.5; 3.77881728605]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 160.06664674° = 160°3'59″ = 0.34879057754 rad
∠ B' = β' = 99.96767663002° = 99°58' = 1.39768434391 rad
∠ C' = γ' = 99.96767663002° = 99°58' = 1.39768434391 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.