# 6 21 26 triangle

### Obtuse scalene triangle.

Sides: a = 6   b = 21   c = 26

Area: T = 38.65114876816
Perimeter: p = 53
Semiperimeter: s = 26.5

Angle ∠ A = α = 8.13993156701° = 8°8'22″ = 0.14220578573 rad
Angle ∠ B = β = 29.70548301032° = 29°42'17″ = 0.5188447089 rad
Angle ∠ C = γ = 142.1565854227° = 142°9'21″ = 2.48110877072 rad

Height: ha = 12.88438292272
Height: hb = 3.68110940649
Height: hc = 2.97331913601

Median: ma = 23.44114163395
Median: mb = 15.67664154066
Median: mc = 8.33766660003

Inradius: r = 1.4598546705
Circumradius: R = 21.18993525741

Vertex coordinates: A[26; 0] B[0; 0] C[5.21215384615; 2.97331913601]
Centroid: CG[10.40438461538; 0.99110637867]
Coordinates of the circumscribed circle: U[13; -16.7332861755]
Coordinates of the inscribed circle: I[5.5; 1.4598546705]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 171.861068433° = 171°51'38″ = 0.14220578573 rad
∠ B' = β' = 150.2955169897° = 150°17'43″ = 0.5188447089 rad
∠ C' = γ' = 37.84441457733° = 37°50'39″ = 2.48110877072 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.