# 15 18 22 triangle

### Acute scalene triangle.

Sides: a = 15   b = 18   c = 22

Area: T = 134.0188422241
Perimeter: p = 55
Semiperimeter: s = 27.5

Angle ∠ A = α = 42.59988128925° = 42°35'56″ = 0.74334895424 rad
Angle ∠ B = β = 54.31546652873° = 54°18'53″ = 0.94879697414 rad
Angle ∠ C = γ = 83.08765218202° = 83°5'11″ = 1.45501333698 rad

Height: ha = 17.86991229655
Height: hb = 14.89109358046
Height: hc = 12.1833492931

Median: ma = 18.6488056199
Median: mb = 16.53878354085
Median: mc = 12.39895116934

Inradius: r = 4.87333971724
Circumradius: R = 11.08105662025

Vertex coordinates: A[22; 0] B[0; 0] C[8.75; 12.1833492931]
Centroid: CG[10.25; 4.06111643103]
Coordinates of the circumscribed circle: U[11; 1.33437718577]
Coordinates of the inscribed circle: I[9.5; 4.87333971724]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 137.4011187108° = 137°24'4″ = 0.74334895424 rad
∠ B' = β' = 125.6855334713° = 125°41'7″ = 0.94879697414 rad
∠ C' = γ' = 96.91334781798° = 96°54'49″ = 1.45501333698 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.