# 17 20 26 triangle

### Acute scalene triangle.

Sides: a = 17   b = 20   c = 26

Area: T = 169.9698930984
Perimeter: p = 63
Semiperimeter: s = 31.5

Angle ∠ A = α = 40.82331687687° = 40°49'23″ = 0.71224987061 rad
Angle ∠ B = β = 50.27222584558° = 50°16'20″ = 0.87774164325 rad
Angle ∠ C = γ = 88.90545727755° = 88°54'16″ = 1.5521677515 rad

Height: ha = 19.99663448217
Height: hb = 16.99768930984
Height: hc = 13.07545331527

Median: ma = 21.58112418549
Median: mb = 19.55876072156
Median: mc = 13.24876412995

Inradius: r = 5.39658390789
Circumradius: R = 13.00223763002

Vertex coordinates: A[26; 0] B[0; 0] C[10.86553846154; 13.07545331527]
Centroid: CG[12.28884615385; 4.35881777176]
Coordinates of the circumscribed circle: U[13; 0.2498574841]
Coordinates of the inscribed circle: I[11.5; 5.39658390789]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.1776831231° = 139°10'37″ = 0.71224987061 rad
∠ B' = β' = 129.7287741544° = 129°43'40″ = 0.87774164325 rad
∠ C' = γ' = 91.09554272245° = 91°5'44″ = 1.5521677515 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.