# 11 20 23 triangle

### Obtuse scalene triangle.

Sides: a = 11   b = 20   c = 23

Area: T = 109.9821816679
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 28.56767204538° = 28°34' = 0.49985833284 rad
Angle ∠ B = β = 60.39114806958° = 60°23'29″ = 1.05440301783 rad
Angle ∠ C = γ = 91.04217988505° = 91°2'30″ = 1.58989791469 rad

Height: ha = 19.99766939416
Height: hb = 10.99881816679
Height: hc = 9.5643636233

Median: ma = 20.83986659842
Median: mb = 15
Median: mc = 11.32547516529

Inradius: r = 4.07334006177
Circumradius: R = 11.50219012979

Vertex coordinates: A[23; 0] B[0; 0] C[5.43547826087; 9.5643636233]
Centroid: CG[9.47882608696; 3.18878787443]
Coordinates of the circumscribed circle: U[11.5; -0.20991254781]
Coordinates of the inscribed circle: I[7; 4.07334006177]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.4333279546° = 151°26' = 0.49985833284 rad
∠ B' = β' = 119.6098519304° = 119°36'31″ = 1.05440301783 rad
∠ C' = γ' = 88.95882011495° = 88°57'30″ = 1.58989791469 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.