# 18 20 23 triangle

### Acute scalene triangle.

Sides: a = 18   b = 20   c = 23

Area: T = 173.2732725782
Perimeter: p = 61
Semiperimeter: s = 30.5

Angle ∠ A = α = 48.88222476784° = 48°52'56″ = 0.85331561678 rad
Angle ∠ B = β = 56.83216133696° = 56°49'54″ = 0.99218987725 rad
Angle ∠ C = γ = 74.2866138952° = 74°17'10″ = 1.29765377133 rad

Height: ha = 19.25325250869
Height: hb = 17.32772725782
Height: hc = 15.06771935463

Median: ma = 19.58331560276
Median: mb = 18.06993109996
Median: mc = 15.15875063912

Inradius: r = 5.68110729765
Circumradius: R = 11.94664848877

Vertex coordinates: A[23; 0] B[0; 0] C[9.8487826087; 15.06771935463]
Centroid: CG[10.94992753623; 5.02223978488]
Coordinates of the circumscribed circle: U[11.5; 3.23655063237]
Coordinates of the inscribed circle: I[10.5; 5.68110729765]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 131.1187752322° = 131°7'4″ = 0.85331561678 rad
∠ B' = β' = 123.168838663° = 123°10'6″ = 0.99218987725 rad
∠ C' = γ' = 105.7143861048° = 105°42'50″ = 1.29765377133 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.