# 11 12 12 triangle

### Acute isosceles triangle.

Sides: a = 11   b = 12   c = 12

Area: T = 58.66595047712
Perimeter: p = 35
Semiperimeter: s = 17.5

Angle ∠ A = α = 54.5599225472° = 54°33'33″ = 0.95222381218 rad
Angle ∠ B = β = 62.7220387264° = 62°43'13″ = 1.09546772659 rad
Angle ∠ C = γ = 62.7220387264° = 62°43'13″ = 1.09546772659 rad

Height: ha = 10.66553645039
Height: hb = 9.77765841285
Height: hc = 9.77765841285

Median: ma = 10.66553645039
Median: mb = 9.82334413522
Median: mc = 9.82334413522

Inradius: r = 3.35219717012
Circumradius: R = 6.75108241255

Vertex coordinates: A[12; 0] B[0; 0] C[5.04216666667; 9.77765841285]
Centroid: CG[5.68105555556; 3.25988613762]
Coordinates of the circumscribed circle: U[6; 3.09441277242]
Coordinates of the inscribed circle: I[5.5; 3.35219717012]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 125.4410774528° = 125°26'27″ = 0.95222381218 rad
∠ B' = β' = 117.2879612736° = 117°16'47″ = 1.09546772659 rad
∠ C' = γ' = 117.2879612736° = 117°16'47″ = 1.09546772659 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.