# 10 18 25 triangle

### Obtuse scalene triangle.

Sides: a = 10   b = 18   c = 25

Area: T = 74.66655040832
Perimeter: p = 53
Semiperimeter: s = 26.5

Angle ∠ A = α = 19.38109001271° = 19°22'51″ = 0.33882605192 rad
Angle ∠ B = β = 36.67884850469° = 36°40'43″ = 0.64401603287 rad
Angle ∠ C = γ = 123.9410614826° = 123°56'26″ = 2.16331718057 rad

Height: ha = 14.93331008166
Height: hb = 8.29661671204
Height: hc = 5.97332403267

Median: ma = 21.20114150471
Median: mb = 16.77879617356
Median: mc = 7.46765922615

Inradius: r = 2.81875661918
Circumradius: R = 15.06771988867

Vertex coordinates: A[25; 0] B[0; 0] C[8.02; 5.97332403267]
Centroid: CG[11.00766666667; 1.99110801089]
Coordinates of the circumscribed circle: U[12.5; -8.41325193784]
Coordinates of the inscribed circle: I[8.5; 2.81875661918]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 160.6199099873° = 160°37'9″ = 0.33882605192 rad
∠ B' = β' = 143.3221514953° = 143°19'17″ = 0.64401603287 rad
∠ C' = γ' = 56.0599385174° = 56°3'34″ = 2.16331718057 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.