# 3 11 12 triangle

### Obtuse scalene triangle.

Sides: a = 3   b = 11   c = 12

Area: T = 16.12545154966
Perimeter: p = 26
Semiperimeter: s = 13

Angle ∠ A = α = 14.14111102339° = 14°8'28″ = 0.24768089335 rad
Angle ∠ B = β = 63.61222000388° = 63°36'44″ = 1.11102423351 rad
Angle ∠ C = γ = 102.2476689727° = 102°14'48″ = 1.7854541385 rad

Height: ha = 10.75496769977
Height: hb = 2.93217300903
Height: hc = 2.68774192494

Median: ma = 11.41327122105
Median: mb = 6.80107352544
Median: mc = 5.38551648071

Inradius: r = 1.24403473459
Circumradius: R = 6.14397193622

Vertex coordinates: A[12; 0] B[0; 0] C[1.33333333333; 2.68774192494]
Centroid: CG[4.44444444444; 0.89658064165]
Coordinates of the circumscribed circle: U[6; -1.30223647132]
Coordinates of the inscribed circle: I[2; 1.24403473459]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 165.8598889766° = 165°51'32″ = 0.24768089335 rad
∠ B' = β' = 116.3887799961° = 116°23'16″ = 1.11102423351 rad
∠ C' = γ' = 77.75333102727° = 77°45'12″ = 1.7854541385 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.