# 18 23 30 triangle

### Obtuse scalene triangle.

Sides: a = 18   b = 23   c = 30

Area: T = 206.6666246639
Perimeter: p = 71
Semiperimeter: s = 35.5

Angle ∠ A = α = 36.80106440229° = 36°48'2″ = 0.64222924051 rad
Angle ∠ B = β = 49.94553102552° = 49°56'43″ = 0.87217101099 rad
Angle ∠ C = γ = 93.25440457219° = 93°15'15″ = 1.62875901387 rad

Height: ha = 22.96329162933
Height: hb = 17.97109779686
Height: hc = 13.7787749776

Median: ma = 25.16994258973
Median: mb = 21.90331961138
Median: mc = 14.19550695666

Inradius: r = 5.82215844124
Circumradius: R = 15.02442240835

Vertex coordinates: A[30; 0] B[0; 0] C[11.58333333333; 13.7787749776]
Centroid: CG[13.86111111111; 4.59325832587]
Coordinates of the circumscribed circle: U[15; -0.85328243139]
Coordinates of the inscribed circle: I[12.5; 5.82215844124]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 143.1999355977° = 143°11'58″ = 0.64222924051 rad
∠ B' = β' = 130.0554689745° = 130°3'17″ = 0.87217101099 rad
∠ C' = γ' = 86.74659542781° = 86°44'45″ = 1.62875901387 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.