# 12 16 26 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 16   c = 26

Area: T = 66.74657863839
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 18.71769506574° = 18°43'1″ = 0.32766724149 rad
Angle ∠ B = β = 25.33216750167° = 25°19'54″ = 0.44221211341 rad
Angle ∠ C = γ = 135.9511374326° = 135°57'5″ = 2.37327991046 rad

Height: ha = 11.12442977306
Height: hb = 8.3433223298
Height: hc = 5.13442912603

Median: ma = 20.73664413533
Median: mb = 18.60110752377
Median: mc = 5.56877643628

Inradius: r = 2.47220661624
Circumradius: R = 18.6987809519

Vertex coordinates: A[26; 0] B[0; 0] C[10.84661538462; 5.13442912603]
Centroid: CG[12.28220512821; 1.71114304201]
Coordinates of the circumscribed circle: U[13; -13.43990505918]
Coordinates of the inscribed circle: I[11; 2.47220661624]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.2833049343° = 161°16'59″ = 0.32766724149 rad
∠ B' = β' = 154.6688324983° = 154°40'6″ = 0.44221211341 rad
∠ C' = γ' = 44.04986256741° = 44°2'55″ = 2.37327991046 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.