# 13 25 30 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 25   c = 30

Area: T = 160.3254670591
Perimeter: p = 68
Semiperimeter: s = 34

Angle ∠ A = α = 25.31110651555° = 25°18'40″ = 0.44217614242 rad
Angle ∠ B = β = 55.30333976437° = 55°18'12″ = 0.96552263764 rad
Angle ∠ C = γ = 99.38655372008° = 99°23'8″ = 1.7354604853 rad

Height: ha = 24.6655333937
Height: hb = 12.82659736473
Height: hc = 10.68883113727

Median: ma = 26.83774738006
Median: mb = 19.44986503388
Median: mc = 13.11548770486

Inradius: r = 4.7155431488
Circumradius: R = 15.20435241427

Vertex coordinates: A[30; 0] B[0; 0] C[7.4; 10.68883113727]
Centroid: CG[12.46766666667; 3.56327704576]
Coordinates of the circumscribed circle: U[15; -2.47993439371]
Coordinates of the inscribed circle: I[9; 4.7155431488]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 154.6898934845° = 154°41'20″ = 0.44217614242 rad
∠ B' = β' = 124.6976602356° = 124°41'48″ = 0.96552263764 rad
∠ C' = γ' = 80.61444627992° = 80°36'52″ = 1.7354604853 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.