# 11 11 15 triangle

### Acute isosceles triangle.

Sides: a = 11   b = 11   c = 15

Area: T = 60.35105385229
Perimeter: p = 37
Semiperimeter: s = 18.5

Angle ∠ A = α = 47.01441139198° = 47°51″ = 0.82105510828 rad
Angle ∠ B = β = 47.01441139198° = 47°51″ = 0.82105510828 rad
Angle ∠ C = γ = 85.97217721604° = 85°58'18″ = 1.5500490488 rad

Height: ha = 10.9732825186
Height: hb = 10.9732825186
Height: hc = 8.04767384697

Median: ma = 11.94878031453
Median: mb = 11.94878031453
Median: mc = 8.04767384697

Inradius: r = 3.26221912715
Circumradius: R = 7.51985741686

Vertex coordinates: A[15; 0] B[0; 0] C[7.5; 8.04767384697]
Centroid: CG[7.5; 2.68222461566]
Coordinates of the circumscribed circle: U[7.5; 0.52881643011]
Coordinates of the inscribed circle: I[7.5; 3.26221912715]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 132.986588608° = 132°59'9″ = 0.82105510828 rad
∠ B' = β' = 132.986588608° = 132°59'9″ = 0.82105510828 rad
∠ C' = γ' = 94.02882278396° = 94°1'42″ = 1.5500490488 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.