# 2 12 12 triangle

### Acute isosceles triangle.

Sides: a = 2   b = 12   c = 12

Area: T = 11.95882607431
Perimeter: p = 26
Semiperimeter: s = 13

Angle ∠ A = α = 9.56603836944° = 9°33'37″ = 0.16768601732 rad
Angle ∠ B = β = 85.22198081528° = 85°13'11″ = 1.48773662402 rad
Angle ∠ C = γ = 85.22198081528° = 85°13'11″ = 1.48773662402 rad

Height: ha = 11.95882607431
Height: hb = 1.99330434572
Height: hc = 1.99330434572

Median: ma = 11.95882607431
Median: mb = 6.1644414003
Median: mc = 6.1644414003

Inradius: r = 0.9219866211
Circumradius: R = 6.02109424721

Vertex coordinates: A[12; 0] B[0; 0] C[0.16766666667; 1.99330434572]
Centroid: CG[4.05655555556; 0.66443478191]
Coordinates of the circumscribed circle: U[6; 0.5021745206]
Coordinates of the inscribed circle: I[1; 0.9219866211]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 170.4439616306° = 170°26'23″ = 0.16768601732 rad
∠ B' = β' = 94.78801918472° = 94°46'49″ = 1.48773662402 rad
∠ C' = γ' = 94.78801918472° = 94°46'49″ = 1.48773662402 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.