# 8 18 25 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 18   c = 25

Area: T = 40.90876704299
Perimeter: p = 51
Semiperimeter: s = 25.5

Angle ∠ A = α = 10.47553138432° = 10°28'31″ = 0.18328287167 rad
Angle ∠ B = β = 24.14768479965° = 24°8'49″ = 0.42114420015 rad
Angle ∠ C = γ = 145.378783816° = 145°22'40″ = 2.53773219353 rad

Height: ha = 10.22769176075
Height: hb = 4.54552967144
Height: hc = 3.27326136344

Median: ma = 21.41326131054
Median: mb = 16.23326830807
Median: mc = 6.14441028637

Inradius: r = 1.60442223698
Circumradius: R = 22.00107639287

Vertex coordinates: A[25; 0] B[0; 0] C[7.3; 3.27326136344]
Centroid: CG[10.76766666667; 1.09108712115]
Coordinates of the circumscribed circle: U[12.5; -18.10547953163]
Coordinates of the inscribed circle: I[7.5; 1.60442223698]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 169.5254686157° = 169°31'29″ = 0.18328287167 rad
∠ B' = β' = 155.8533152003° = 155°51'11″ = 0.42114420015 rad
∠ C' = γ' = 34.62221618397° = 34°37'20″ = 2.53773219353 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.