# 28 30 30 triangle

### Acute isosceles triangle.

Sides: a = 28   b = 30   c = 30

Area: T = 371.462197652
Perimeter: p = 88
Semiperimeter: s = 44

Angle ∠ A = α = 55.63662785693° = 55°38'11″ = 0.97110362446 rad
Angle ∠ B = β = 62.18218607153° = 62°10'55″ = 1.08552782045 rad
Angle ∠ C = γ = 62.18218607153° = 62°10'55″ = 1.08552782045 rad

Height: ha = 26.53329983228
Height: hb = 24.7644131768
Height: hc = 24.7644131768

Median: ma = 26.53329983228
Median: mb = 24.83994846967
Median: mc = 24.83994846967

Inradius: r = 8.44223176482
Circumradius: R = 16.96600131325

Vertex coordinates: A[30; 0] B[0; 0] C[13.06766666667; 24.7644131768]
Centroid: CG[14.35655555556; 8.25547105893]
Coordinates of the circumscribed circle: U[15; 7.91546727952]
Coordinates of the inscribed circle: I[14; 8.44223176482]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 124.3643721431° = 124°21'49″ = 0.97110362446 rad
∠ B' = β' = 117.8188139285° = 117°49'5″ = 1.08552782045 rad
∠ C' = γ' = 117.8188139285° = 117°49'5″ = 1.08552782045 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.