# 8 11 12 triangle

### Acute scalene triangle.

Sides: a = 8   b = 11   c = 12

Area: T = 42.78994554768
Perimeter: p = 31
Semiperimeter: s = 15.5

Angle ∠ A = α = 40.41554390215° = 40°24'56″ = 0.70553824796 rad
Angle ∠ B = β = 63.05656418195° = 63°3'20″ = 1.10105285617 rad
Angle ∠ C = γ = 76.5298919159° = 76°31'44″ = 1.33656816123 rad

Height: ha = 10.69773638692
Height: hb = 7.78799009958
Height: hc = 7.13215759128

Median: ma = 10.79435165725
Median: mb = 8.58877820187
Median: mc = 7.51766481892

Inradius: r = 2.76106100308
Circumradius: R = 6.17697443227

Vertex coordinates: A[12; 0] B[0; 0] C[3.625; 7.13215759128]
Centroid: CG[5.20883333333; 2.37771919709]
Coordinates of the circumscribed circle: U[6; 1.43772699843]
Coordinates of the inscribed circle: I[4.5; 2.76106100308]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.5854560979° = 139°35'4″ = 0.70553824796 rad
∠ B' = β' = 116.944435818° = 116°56'40″ = 1.10105285617 rad
∠ C' = γ' = 103.4711080841° = 103°28'16″ = 1.33656816123 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.