# 16 17 18 triangle

### Acute scalene triangle.

Sides: a = 16   b = 17   c = 18

Area: T = 124.2721627896
Perimeter: p = 51
Semiperimeter: s = 25.5

Angle ∠ A = α = 54.31546652873° = 54°18'53″ = 0.94879697414 rad
Angle ∠ B = β = 59.65548170304° = 59°39'17″ = 1.04111729719 rad
Angle ∠ C = γ = 66.03105176822° = 66°1'50″ = 1.15224499404 rad

Height: ha = 15.5343953487
Height: hb = 14.62201915172
Height: hc = 13.80879586551

Median: ma = 15.57224115024
Median: mb = 14.75663545634
Median: mc = 13.83883525031

Inradius: r = 4.87333971724
Circumradius: R = 9.849939218

Vertex coordinates: A[18; 0] B[0; 0] C[8.08333333333; 13.80879586551]
Centroid: CG[8.69444444444; 4.6032652885]
Coordinates of the circumscribed circle: U[9; 4.00113155731]
Coordinates of the inscribed circle: I[8.5; 4.87333971724]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 125.6855334713° = 125°41'7″ = 0.94879697414 rad
∠ B' = β' = 120.345518297° = 120°20'43″ = 1.04111729719 rad
∠ C' = γ' = 113.9699482318° = 113°58'10″ = 1.15224499404 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.