# 15 15 22 triangle

### Obtuse isosceles triangle.

Sides: a = 15   b = 15   c = 22

Area: T = 112.1788429299
Perimeter: p = 52
Semiperimeter: s = 26

Angle ∠ A = α = 42.83334280661° = 42°50' = 0.74875843497 rad
Angle ∠ B = β = 42.83334280661° = 42°50' = 0.74875843497 rad
Angle ∠ C = γ = 94.33331438679° = 94°19'59″ = 1.64664239543 rad

Height: ha = 14.95771239065
Height: hb = 14.95771239065
Height: hc = 10.19880390272

Median: ma = 17.27699160392
Median: mb = 17.27699160392
Median: mc = 10.19880390272

Inradius: r = 4.3154554973
Circumradius: R = 11.03215326015

Vertex coordinates: A[22; 0] B[0; 0] C[11; 10.19880390272]
Centroid: CG[11; 3.39993463424]
Coordinates of the circumscribed circle: U[11; -0.83334935743]
Coordinates of the inscribed circle: I[11; 4.3154554973]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 137.1676571934° = 137°10' = 0.74875843497 rad
∠ B' = β' = 137.1676571934° = 137°10' = 0.74875843497 rad
∠ C' = γ' = 85.66768561321° = 85°40'1″ = 1.64664239543 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.