# 8 12 17 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 12   c = 17

Area: T = 43.51993922292
Perimeter: p = 37
Semiperimeter: s = 18.5

Angle ∠ A = α = 25.25658261791° = 25°15'21″ = 0.44107973221 rad
Angle ∠ B = β = 39.79111530332° = 39°47'28″ = 0.69444866336 rad
Angle ∠ C = γ = 114.9533020788° = 114°57'11″ = 2.00663086979 rad

Height: ha = 10.88798480573
Height: hb = 7.25332320382
Height: hc = 5.12199284976

Median: ma = 14.16598022585
Median: mb = 11.85332695911
Median: mc = 5.63547138348

Inradius: r = 2.352239958
Circumradius: R = 9.37551309267

Vertex coordinates: A[17; 0] B[0; 0] C[6.14770588235; 5.12199284976]
Centroid: CG[7.71656862745; 1.70766428325]
Coordinates of the circumscribed circle: U[8.5; -3.95551333597]
Coordinates of the inscribed circle: I[6.5; 2.352239958]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 154.7444173821° = 154°44'39″ = 0.44107973221 rad
∠ B' = β' = 140.2098846967° = 140°12'32″ = 0.69444866336 rad
∠ C' = γ' = 65.04769792123° = 65°2'49″ = 2.00663086979 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.