# 17 21 26 triangle

### Acute scalene triangle.

Sides: a = 17   b = 21   c = 26

Area: T = 177.989876369
Perimeter: p = 64
Semiperimeter: s = 32

Angle ∠ A = α = 40.69105605975° = 40°41'26″ = 0.71101842569 rad
Angle ∠ B = β = 53.64768753478° = 53°38'49″ = 0.93663146082 rad
Angle ∠ C = γ = 85.66325640547° = 85°39'45″ = 1.49550937885 rad

Height: ha = 20.94398545518
Height: hb = 16.95113108276
Height: hc = 13.69114433608

Median: ma = 22.05110770712
Median: mb = 19.29437813816
Median: mc = 14

Inradius: r = 5.56221488653
Circumradius: R = 13.03773398404

Vertex coordinates: A[26; 0] B[0; 0] C[10.07769230769; 13.69114433608]
Centroid: CG[12.02656410256; 4.56438144536]
Coordinates of the circumscribed circle: U[13; 0.98660172989]
Coordinates of the inscribed circle: I[11; 5.56221488653]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.3099439402° = 139°18'34″ = 0.71101842569 rad
∠ B' = β' = 126.3533124652° = 126°21'11″ = 0.93663146082 rad
∠ C' = γ' = 94.33774359453° = 94°20'15″ = 1.49550937885 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.