# 14 18 25 triangle

### Obtuse scalene triangle.

Sides: a = 14   b = 18   c = 25

Area: T = 123.235529324
Perimeter: p = 57
Semiperimeter: s = 28.5

Angle ∠ A = α = 33.21102161481° = 33°12'37″ = 0.58796276171 rad
Angle ∠ B = β = 44.76550846713° = 44°45'54″ = 0.78112981174 rad
Angle ∠ C = γ = 102.0254699181° = 102°1'29″ = 1.78106669191 rad

Height: ha = 17.60550418915
Height: hb = 13.693281036
Height: hc = 9.85988234592

Median: ma = 20.62876513447
Median: mb = 18.15221348607
Median: mc = 10.18657743937

Inradius: r = 4.32440453768
Circumradius: R = 12.78804296853

Vertex coordinates: A[25; 0] B[0; 0] C[9.94; 9.85988234592]
Centroid: CG[11.64766666667; 3.28662744864]
Coordinates of the circumscribed circle: U[12.5; -2.66325895178]
Coordinates of the inscribed circle: I[10.5; 4.32440453768]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 146.7989783852° = 146°47'23″ = 0.58796276171 rad
∠ B' = β' = 135.2354915329° = 135°14'6″ = 0.78112981174 rad
∠ C' = γ' = 77.97553008194° = 77°58'31″ = 1.78106669191 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    