# 17 18 25 triangle

### Obtuse scalene triangle.

Sides: a = 17   b = 18   c = 25

Area: T = 152.9710585408
Perimeter: p = 60
Semiperimeter: s = 30

Angle ∠ A = α = 42.83334280661° = 42°50' = 0.74875843497 rad
Angle ∠ B = β = 46.04330532762° = 46°2'35″ = 0.80436028773 rad
Angle ∠ C = γ = 91.12435186577° = 91°7'25″ = 1.59904054266 rad

Height: ha = 17.99765394597
Height: hb = 16.9976731712
Height: hc = 12.23876468326

Median: ma = 20.05661711201
Median: mb = 19.39107194297
Median: mc = 12.25876506721

Inradius: r = 5.09990195136
Circumradius: R = 12.50224036151

Vertex coordinates: A[25; 0] B[0; 0] C[11.8; 12.23876468326]
Centroid: CG[12.26766666667; 4.07992156109]
Coordinates of the circumscribed circle: U[12.5; -0.24551451689]
Coordinates of the inscribed circle: I[12; 5.09990195136]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 137.1676571934° = 137°10' = 0.74875843497 rad
∠ B' = β' = 133.9576946724° = 133°57'25″ = 0.80436028773 rad
∠ C' = γ' = 88.87664813423° = 88°52'35″ = 1.59904054266 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.