# 13 16 25 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 16   c = 25

Area: T = 91.19221049214
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 27.12767531173° = 27°7'36″ = 0.47334511573 rad
Angle ∠ B = β = 34.13875931378° = 34°8'15″ = 0.5965813399 rad
Angle ∠ C = γ = 118.7365653745° = 118°44'8″ = 2.07223280974 rad

Height: ha = 14.03295546033
Height: hb = 11.39990131152
Height: hc = 7.29553683937

Median: ma = 19.95662020435
Median: mb = 18.24882875909
Median: mc = 7.5

Inradius: r = 3.37774853675
Circumradius: R = 14.25656200575

Vertex coordinates: A[25; 0] B[0; 0] C[10.76; 7.29553683937]
Centroid: CG[11.92; 2.43217894646]
Coordinates of the circumscribed circle: U[12.5; -6.85436634892]
Coordinates of the inscribed circle: I[11; 3.37774853675]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 152.8733246883° = 152°52'24″ = 0.47334511573 rad
∠ B' = β' = 145.8622406862° = 145°51'45″ = 0.5965813399 rad
∠ C' = γ' = 61.26443462551° = 61°15'52″ = 2.07223280974 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.