# 1 12 12 triangle

### Acute isosceles triangle.

Sides: a = 1   b = 12   c = 12

Area: T = 5.99547894041
Perimeter: p = 25
Semiperimeter: s = 12.5

Angle ∠ A = α = 4.77660309265° = 4°46'34″ = 0.08333574648 rad
Angle ∠ B = β = 87.61219845367° = 87°36'43″ = 1.52991175944 rad
Angle ∠ C = γ = 87.61219845367° = 87°36'43″ = 1.52991175944 rad

Height: ha = 11.99895788083
Height: hb = 0.99991315674
Height: hc = 0.99991315674

Median: ma = 11.99895788083
Median: mb = 6.04215229868
Median: mc = 6.04215229868

Inradius: r = 0.48795831523
Circumradius: R = 6.00552151248

Vertex coordinates: A[12; 0] B[0; 0] C[0.04216666667; 0.99991315674]
Centroid: CG[4.01438888889; 0.33330438558]
Coordinates of the circumscribed circle: U[6; 0.25502172969]
Coordinates of the inscribed circle: I[0.5; 0.48795831523]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 175.2243969073° = 175°13'26″ = 0.08333574648 rad
∠ B' = β' = 92.38880154633° = 92°23'17″ = 1.52991175944 rad
∠ C' = γ' = 92.38880154633° = 92°23'17″ = 1.52991175944 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.