# 2 13 13 triangle

### Acute isosceles triangle.

Sides: a = 2   b = 13   c = 13

Area: T = 12.96114813968
Perimeter: p = 28
Semiperimeter: s = 14

Angle ∠ A = α = 8.82334515715° = 8°49'24″ = 0.15439982813 rad
Angle ∠ B = β = 85.58882742142° = 85°35'18″ = 1.49437971861 rad
Angle ∠ C = γ = 85.58882742142° = 85°35'18″ = 1.49437971861 rad

Height: ha = 12.96114813968
Height: hb = 1.9944074061
Height: hc = 1.9944074061

Median: ma = 12.96114813968
Median: mb = 6.65220673478
Median: mc = 6.65220673478

Inradius: r = 0.92658200998
Circumradius: R = 6.51993165359

Vertex coordinates: A[13; 0] B[0; 0] C[0.15438461538; 1.9944074061]
Centroid: CG[4.38546153846; 0.66546913537]
Coordinates of the circumscribed circle: U[6.5; 0.50114858874]
Coordinates of the inscribed circle: I[1; 0.92658200998]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 171.1776548428° = 171°10'36″ = 0.15439982813 rad
∠ B' = β' = 94.41217257858° = 94°24'42″ = 1.49437971861 rad
∠ C' = γ' = 94.41217257858° = 94°24'42″ = 1.49437971861 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.