# 4 15 17 triangle

### Obtuse scalene triangle.

Sides: a = 4   b = 15   c = 17

Area: T = 27.49554541697
Perimeter: p = 36
Semiperimeter: s = 18

Angle ∠ A = α = 12.45437005943° = 12°27'13″ = 0.21773580794 rad
Angle ∠ B = β = 53.96881209275° = 53°58'5″ = 0.94219214013 rad
Angle ∠ C = γ = 113.5788178478° = 113°34'41″ = 1.98223131729 rad

Height: ha = 13.74877270849
Height: hb = 3.6666060556
Height: hc = 3.23547593141

Median: ma = 15.90659737206
Median: mb = 9.81107084352
Median: mc = 6.94662219947

Inradius: r = 1.52875252317
Circumradius: R = 9.2744260335

Vertex coordinates: A[17; 0] B[0; 0] C[2.35329411765; 3.23547593141]
Centroid: CG[6.45109803922; 1.07882531047]
Coordinates of the circumscribed circle: U[8.5; -3.7109704134]
Coordinates of the inscribed circle: I[3; 1.52875252317]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 167.5466299406° = 167°32'47″ = 0.21773580794 rad
∠ B' = β' = 126.0321879072° = 126°1'55″ = 0.94219214013 rad
∠ C' = γ' = 66.42218215218° = 66°25'19″ = 1.98223131729 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.