# 10 20 26 triangle

### Obtuse scalene triangle.

Sides: a = 10   b = 20   c = 26

Area: T = 89.87997772826
Perimeter: p = 56
Semiperimeter: s = 28

Angle ∠ A = α = 20.20552235834° = 20°12'19″ = 0.35326476776 rad
Angle ∠ B = β = 43.69108952793° = 43°41'27″ = 0.76325499758 rad
Angle ∠ C = γ = 116.1043881137° = 116°6'14″ = 2.02663950002 rad

Height: ha = 17.96599554565
Height: hb = 8.98799777283
Height: hc = 6.90876751756

Median: ma = 22.65495033058
Median: mb = 16.97105627485
Median: mc = 9

Inradius: r = 3.20771349029
Circumradius: R = 14.47766506036

Vertex coordinates: A[26; 0] B[0; 0] C[7.23107692308; 6.90876751756]
Centroid: CG[11.07769230769; 2.30325583919]
Coordinates of the circumscribed circle: U[13; -6.37697262656]
Coordinates of the inscribed circle: I[8; 3.20771349029]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 159.7954776417° = 159°47'41″ = 0.35326476776 rad
∠ B' = β' = 136.3099104721° = 136°18'33″ = 0.76325499758 rad
∠ C' = γ' = 63.89661188627° = 63°53'46″ = 2.02663950002 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.