# 20 26 30 triangle

### Acute scalene triangle.

Sides: a = 20   b = 26   c = 30

Area: T = 256.2549878049
Perimeter: p = 76
Semiperimeter: s = 38

Angle ∠ A = α = 41.07553488744° = 41°4'31″ = 0.71769000793 rad
Angle ∠ B = β = 58.66877485024° = 58°40'4″ = 1.02439453761 rad
Angle ∠ C = γ = 80.25769026232° = 80°15'25″ = 1.40107471982 rad

Height: ha = 25.62549878049
Height: hb = 19.71215290807
Height: hc = 17.08333252033

Median: ma = 26.23297540972
Median: mb = 21.93217121995
Median: mc = 17.6921806013

Inradius: r = 6.74334178434
Circumradius: R = 15.22195194382

Vertex coordinates: A[30; 0] B[0; 0] C[10.4; 17.08333252033]
Centroid: CG[13.46766666667; 5.69444417344]
Coordinates of the circumscribed circle: U[15; 2.57656109818]
Coordinates of the inscribed circle: I[12; 6.74334178434]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 138.9254651126° = 138°55'29″ = 0.71769000793 rad
∠ B' = β' = 121.3322251498° = 121°19'56″ = 1.02439453761 rad
∠ C' = γ' = 99.74330973768° = 99°44'35″ = 1.40107471982 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.