# 12 19 30 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 19   c = 30

Area: T = 56.96599640098
Perimeter: p = 61
Semiperimeter: s = 30.5

Angle ∠ A = α = 11.52987444337° = 11°31'43″ = 0.2011214549 rad
Angle ∠ B = β = 18.448802355° = 18°26'53″ = 0.32219787514 rad
Angle ∠ C = γ = 150.0233232016° = 150°1'24″ = 2.61883993532 rad

Height: ha = 9.4933327335
Height: hb = 5.99657856852
Height: hc = 3.7977330934

Median: ma = 24.38223706805
Median: mb = 20.77985947552
Median: mc = 5.24440442409

Inradius: r = 1.86875398036
Circumradius: R = 30.02110863846

Vertex coordinates: A[30; 0] B[0; 0] C[11.38333333333; 3.7977330934]
Centroid: CG[13.79444444444; 1.2665776978]
Coordinates of the circumscribed circle: U[15; -26.00551077235]
Coordinates of the inscribed circle: I[11.5; 1.86875398036]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 168.4711255566° = 168°28'17″ = 0.2011214549 rad
∠ B' = β' = 161.552197645° = 161°33'7″ = 0.32219787514 rad
∠ C' = γ' = 29.97767679837° = 29°58'36″ = 2.61883993532 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.