# 8 13 17 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 13   c = 17

Area: T = 50.08799361022
Perimeter: p = 38
Semiperimeter: s = 19

Angle ∠ A = α = 26.95499559276° = 26°57' = 0.47703654642 rad
Angle ∠ B = β = 47.43215457967° = 47°25'54″ = 0.82878366435 rad
Angle ∠ C = γ = 105.6188498276° = 105°37'7″ = 1.84333905459 rad

Height: ha = 12.52199840255
Height: hb = 7.70546055542
Height: hc = 5.89217571885

Median: ma = 14.59545195193
Median: mb = 11.58766302263
Median: mc = 6.65220673478

Inradius: r = 2.63657861106
Circumradius: R = 8.82658898553

Vertex coordinates: A[17; 0] B[0; 0] C[5.41217647059; 5.89217571885]
Centroid: CG[7.47105882353; 1.96439190628]
Coordinates of the circumscribed circle: U[8.5; -2.37662011149]
Coordinates of the inscribed circle: I[6; 2.63657861106]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 153.0550044072° = 153°3' = 0.47703654642 rad
∠ B' = β' = 132.5688454203° = 132°34'6″ = 0.82878366435 rad
∠ C' = γ' = 74.38215017244° = 74°22'53″ = 1.84333905459 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.