# 9 20 23 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 20   c = 23

Area: T = 89.19664124839
Perimeter: p = 52
Semiperimeter: s = 26

Angle ∠ A = α = 22.81883300648° = 22°49'6″ = 0.39882549894 rad
Angle ∠ B = β = 59.51994142744° = 59°31'10″ = 1.03988097479 rad
Angle ∠ C = γ = 97.66222556608° = 97°39'44″ = 1.70545279162 rad

Height: ha = 19.82114249964
Height: hb = 8.92196412484
Height: hc = 7.75662097812

Median: ma = 21.07772389084
Median: mb = 14.31878210633
Median: mc = 10.40443260233

Inradius: r = 3.43106312494
Circumradius: R = 11.60436056964

Vertex coordinates: A[23; 0] B[0; 0] C[4.56552173913; 7.75662097812]
Centroid: CG[9.18884057971; 2.58554032604]
Coordinates of the circumscribed circle: U[11.5; -1.54771474262]
Coordinates of the inscribed circle: I[6; 3.43106312494]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 157.1821669935° = 157°10'54″ = 0.39882549894 rad
∠ B' = β' = 120.4810585726° = 120°28'50″ = 1.03988097479 rad
∠ C' = γ' = 82.33877443392° = 82°20'16″ = 1.70545279162 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.