# 6 7 12 triangle

### Obtuse scalene triangle.

Sides: a = 6   b = 7   c = 12

Area: T = 14.94878259289
Perimeter: p = 25
Semiperimeter: s = 12.5

Angle ∠ A = α = 20.84986512302° = 20°50'55″ = 0.36438776086 rad
Angle ∠ B = β = 24.5333007117° = 24°31'59″ = 0.42881817496 rad
Angle ∠ C = γ = 134.6188341653° = 134°37'6″ = 2.35495332954 rad

Height: ha = 4.9832608643
Height: hb = 4.27108074083
Height: hc = 2.49113043215

Median: ma = 9.35441434669
Median: mb = 8.81875960443
Median: mc = 2.55495097568

Inradius: r = 1.19658260743
Circumradius: R = 8.42993194609

Vertex coordinates: A[12; 0] B[0; 0] C[5.45883333333; 2.49113043215]
Centroid: CG[5.81994444444; 0.83304347738]
Coordinates of the circumscribed circle: U[6; -5.92105934309]
Coordinates of the inscribed circle: I[5.5; 1.19658260743]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 159.151134877° = 159°9'5″ = 0.36438776086 rad
∠ B' = β' = 155.4676992883° = 155°28'1″ = 0.42881817496 rad
∠ C' = γ' = 45.38216583472° = 45°22'54″ = 2.35495332954 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.