# 7 20 26 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 20   c = 26

Area: T = 40.9810940692
Perimeter: p = 53
Semiperimeter: s = 26.5

Angle ∠ A = α = 9.0698721546° = 9°4'7″ = 0.15882790499 rad
Angle ∠ B = β = 26.76655005768° = 26°45'56″ = 0.4677146111 rad
Angle ∠ C = γ = 144.1665777877° = 144°9'57″ = 2.51661674927 rad

Height: ha = 11.70988401977
Height: hb = 4.09880940692
Height: hc = 3.15223800532

Median: ma = 22.92992389756
Median: mb = 16.2021851746
Median: mc = 7.45498322129

Inradius: r = 1.54664505922
Circumradius: R = 22.20554444001

Vertex coordinates: A[26; 0] B[0; 0] C[6.25; 3.15223800532]
Centroid: CG[10.75; 1.05107933511]
Coordinates of the circumscribed circle: U[13; -18.00222709958]
Coordinates of the inscribed circle: I[6.5; 1.54664505922]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 170.9311278454° = 170°55'53″ = 0.15882790499 rad
∠ B' = β' = 153.2344499423° = 153°14'4″ = 0.4677146111 rad
∠ C' = γ' = 35.83442221228° = 35°50'3″ = 2.51661674927 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.