# 123 182 105 triangle

### Obtuse scalene triangle.

Sides: a = 123   b = 182   c = 105

Area: T = 6217.958786412
Perimeter: p = 410
Semiperimeter: s = 205

Angle ∠ A = α = 40.59985011963° = 40°35'55″ = 0.70985775172 rad
Angle ∠ B = β = 105.6554821704° = 105°39'17″ = 1.84440245093 rad
Angle ∠ C = γ = 33.74766771001° = 33°44'48″ = 0.5898990627 rad

Height: ha = 101.1055005921
Height: hb = 68.3299207298
Height: hc = 118.437729265

Median: ma = 135.2498844727
Median: mb = 69.25331587727
Median: mc = 146.1865669612

Inradius: r = 30.33215017762
Circumradius: R = 94.50657063495

Vertex coordinates: A[105; 0] B[0; 0] C[-33.19904761905; 118.437729265]
Centroid: CG[23.93765079365; 39.479909755]
Coordinates of the circumscribed circle: U[52.5; 78.58216679169]
Coordinates of the inscribed circle: I[23; 30.33215017762]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.4011498804° = 139°24'5″ = 0.70985775172 rad
∠ B' = β' = 74.34551782964° = 74°20'43″ = 1.84440245093 rad
∠ C' = γ' = 146.25333229° = 146°15'12″ = 0.5898990627 rad

# How did we calculate this triangle?

### 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    