# 15 18 27 triangle

### Obtuse scalene triangle.

Sides: a = 15   b = 18   c = 27

Area: T = 127.2799220614
Perimeter: p = 60
Semiperimeter: s = 30

Angle ∠ A = α = 31.58663380965° = 31°35'11″ = 0.55112855984 rad
Angle ∠ B = β = 38.9422441269° = 38°56'33″ = 0.68796738189 rad
Angle ∠ C = γ = 109.4711220634° = 109°28'16″ = 1.91106332362 rad

Height: ha = 16.97105627485
Height: hb = 14.14221356237
Height: hc = 9.42880904158

Median: ma = 21.68552484422
Median: mb = 19.98997487421
Median: mc = 9.60546863561

Inradius: r = 4.24326406871
Circumradius: R = 14.3198912319

Vertex coordinates: A[27; 0] B[0; 0] C[11.66766666667; 9.42880904158]
Centroid: CG[12.88988888889; 3.14326968053]
Coordinates of the circumscribed circle: U[13.5; -4.7732970773]
Coordinates of the inscribed circle: I[12; 4.24326406871]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 148.4143661903° = 148°24'49″ = 0.55112855984 rad
∠ B' = β' = 141.0587558731° = 141°3'27″ = 0.68796738189 rad
∠ C' = γ' = 70.52987793655° = 70°31'44″ = 1.91106332362 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.