# 13 20 22 triangle

### Acute scalene triangle.

Sides: a = 13   b = 20   c = 22

Area: T = 128.251146198
Perimeter: p = 55
Semiperimeter: s = 27.5

Angle ∠ A = α = 35.65990876961° = 35°39'33″ = 0.62223684886 rad
Angle ∠ B = β = 63.7498786065° = 63°44'56″ = 1.1132626211 rad
Angle ∠ C = γ = 80.59221262388° = 80°35'32″ = 1.40765979541 rad

Height: ha = 19.73109941508
Height: hb = 12.8255146198
Height: hc = 11.65992238164

Median: ma = 19.99437490231
Median: mb = 15.05499169433
Median: mc = 12.78767118525

Inradius: r = 4.66436895265
Circumradius: R = 11.15499703623

Vertex coordinates: A[22; 0] B[0; 0] C[5.75; 11.65992238164]
Centroid: CG[9.25; 3.88664079388]
Coordinates of the circumscribed circle: U[11; 1.82325913092]
Coordinates of the inscribed circle: I[7.5; 4.66436895265]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 144.3410912304° = 144°20'27″ = 0.62223684886 rad
∠ B' = β' = 116.2511213935° = 116°15'4″ = 1.1132626211 rad
∠ C' = γ' = 99.40878737612° = 99°24'28″ = 1.40765979541 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.