# 12 19 25 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 19   c = 25

Area: T = 109.9821816679
Perimeter: p = 56
Semiperimeter: s = 28

Angle ∠ A = α = 27.58661197531° = 27°35'10″ = 0.48114686175 rad
Angle ∠ B = β = 47.15663569564° = 47°9'23″ = 0.82330336921 rad
Angle ∠ C = γ = 105.258752329° = 105°15'27″ = 1.83770903439 rad

Height: ha = 18.33303027798
Height: hb = 11.57770333346
Height: hc = 8.79985453343

Median: ma = 21.37875583264
Median: mb = 17.15437167984
Median: mc = 9.81107084352

Inradius: r = 3.92879220242
Circumradius: R = 12.95766872328

Vertex coordinates: A[25; 0] B[0; 0] C[8.16; 8.79985453343]
Centroid: CG[11.05333333333; 2.93328484448]
Coordinates of the circumscribed circle: U[12.5; -3.41096545349]
Coordinates of the inscribed circle: I[9; 3.92879220242]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 152.4143880247° = 152°24'50″ = 0.48114686175 rad
∠ B' = β' = 132.8443643044° = 132°50'37″ = 0.82330336921 rad
∠ C' = γ' = 74.74224767095° = 74°44'33″ = 1.83770903439 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.