# 12 23 30 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 23   c = 30

Area: T = 125.7911245721
Perimeter: p = 65
Semiperimeter: s = 32.5

Angle ∠ A = α = 21.3843725332° = 21°23'1″ = 0.37332164134 rad
Angle ∠ B = β = 44.33440313162° = 44°20'3″ = 0.77437748172 rad
Angle ∠ C = γ = 114.2822243352° = 114°16'56″ = 1.99546014231 rad

Height: ha = 20.96552076201
Height: hb = 10.93883691931
Height: hc = 8.38660830481

Median: ma = 26.04880325553
Median: mb = 19.74220870224
Median: mc = 10.5599356041

Inradius: r = 3.87704998683
Circumradius: R = 16.4565835127

Vertex coordinates: A[30; 0] B[0; 0] C[8.58333333333; 8.38660830481]
Centroid: CG[12.86111111111; 2.7955361016]
Coordinates of the circumscribed circle: U[15; -6.7677164083]
Coordinates of the inscribed circle: I[9.5; 3.87704998683]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 158.6166274668° = 158°36'59″ = 0.37332164134 rad
∠ B' = β' = 135.6665968684° = 135°39'57″ = 0.77437748172 rad
∠ C' = γ' = 65.71877566482° = 65°43'4″ = 1.99546014231 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.