# 18 19 25 triangle

### Acute scalene triangle.

Sides: a = 18   b = 19   c = 25

Area: T = 170.3410834799
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 45.82658084437° = 45°49'33″ = 0.87998112397 rad
Angle ∠ B = β = 49.20766050518° = 49°12'24″ = 0.85988172719 rad
Angle ∠ C = γ = 84.96875865045° = 84°58'3″ = 1.4832964142 rad

Height: ha = 18.92767594221
Height: hb = 17.93106141894
Height: hc = 13.62772667839

Median: ma = 20.29877831302
Median: mb = 19.60222957839
Median: mc = 13.6477344064

Inradius: r = 5.49548656387
Circumradius: R = 12.54883710499

Vertex coordinates: A[25; 0] B[0; 0] C[11.76; 13.62772667839]
Centroid: CG[12.25333333333; 4.54224222613]
Coordinates of the circumscribed circle: U[12.5; 1.10107343026]
Coordinates of the inscribed circle: I[12; 5.49548656387]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 134.1744191556° = 134°10'27″ = 0.87998112397 rad
∠ B' = β' = 130.7933394948° = 130°47'36″ = 0.85988172719 rad
∠ C' = γ' = 95.03224134955° = 95°1'57″ = 1.4832964142 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.