# 8 10 15 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 10   c = 15

Area: T = 36.97988791069
Perimeter: p = 33
Semiperimeter: s = 16.5

Angle ∠ A = α = 29.54113605001° = 29°32'29″ = 0.51655940062 rad
Angle ∠ B = β = 38.04875074536° = 38°2'51″ = 0.66440542772 rad
Angle ∠ C = γ = 112.4111132046° = 112°24'40″ = 1.96219443701 rad

Height: ha = 9.24547197767
Height: hb = 7.39657758214
Height: hc = 4.93105172142

Median: ma = 12.10437184369
Median: mb = 10.93216055545
Median: mc = 5.07444457825

Inradius: r = 2.24111441883
Circumradius: R = 8.11327391431

Vertex coordinates: A[15; 0] B[0; 0] C[6.3; 4.93105172142]
Centroid: CG[7.1; 1.64435057381]
Coordinates of the circumscribed circle: U[7.5; -3.09329817983]
Coordinates of the inscribed circle: I[6.5; 2.24111441883]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 150.45986395° = 150°27'31″ = 0.51655940062 rad
∠ B' = β' = 141.9522492546° = 141°57'9″ = 0.66440542772 rad
∠ C' = γ' = 67.58988679538° = 67°35'20″ = 1.96219443701 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    