# 11 30 30 triangle

### Acute isosceles triangle.

Sides: a = 11   b = 30   c = 30

Area: T = 162.2033383134
Perimeter: p = 71
Semiperimeter: s = 35.5

Angle ∠ A = α = 21.12879551781° = 21°7'41″ = 0.36987523821 rad
Angle ∠ B = β = 79.43660224109° = 79°26'10″ = 1.38664201358 rad
Angle ∠ C = γ = 79.43660224109° = 79°26'10″ = 1.38664201358 rad

Height: ha = 29.49215242061
Height: hb = 10.81435588756
Height: hc = 10.81435588756

Median: ma = 29.49215242061
Median: mb = 16.89767452487
Median: mc = 16.89767452487

Inradius: r = 4.5699109384
Circumradius: R = 15.25986213196

Vertex coordinates: A[30; 0] B[0; 0] C[2.01766666667; 10.81435588756]
Centroid: CG[10.67222222222; 3.60545196252]
Coordinates of the circumscribed circle: U[15; 2.79774139086]
Coordinates of the inscribed circle: I[5.5; 4.5699109384]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 158.8722044822° = 158°52'19″ = 0.36987523821 rad
∠ B' = β' = 100.5643977589° = 100°33'50″ = 1.38664201358 rad
∠ C' = γ' = 100.5643977589° = 100°33'50″ = 1.38664201358 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.