# 4 30 30 triangle

### Acute isosceles triangle.

Sides: a = 4   b = 30   c = 30

Area: T = 59.86765181884
Perimeter: p = 64
Semiperimeter: s = 32

Angle ∠ A = α = 7.64551074586° = 7°38'42″ = 0.13334322968 rad
Angle ∠ B = β = 86.17774462707° = 86°10'39″ = 1.50440801784 rad
Angle ∠ C = γ = 86.17774462707° = 86°10'39″ = 1.50440801784 rad

Height: ha = 29.93332590942
Height: hb = 3.99111012126
Height: hc = 3.99111012126

Median: ma = 29.93332590942
Median: mb = 15.26443375225
Median: mc = 15.26443375225

Inradius: r = 1.87108286934
Circumradius: R = 15.03334448576

Vertex coordinates: A[30; 0] B[0; 0] C[0.26766666667; 3.99111012126]
Centroid: CG[10.08988888889; 1.33303670709]
Coordinates of the circumscribed circle: U[15; 1.00222296572]
Coordinates of the inscribed circle: I[2; 1.87108286934]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 172.3554892541° = 172°21'18″ = 0.13334322968 rad
∠ B' = β' = 93.82325537293° = 93°49'21″ = 1.50440801784 rad
∠ C' = γ' = 93.82325537293° = 93°49'21″ = 1.50440801784 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.