# 28 28 29 triangle

### Acute isosceles triangle.

Sides: a = 28   b = 28   c = 29

Area: T = 347.3219647443
Perimeter: p = 85
Semiperimeter: s = 42.5

Angle ∠ A = α = 58.81113776665° = 58°48'41″ = 1.02664521779 rad
Angle ∠ B = β = 58.81113776665° = 58°48'41″ = 1.02664521779 rad
Angle ∠ C = γ = 62.3777244667° = 62°22'38″ = 1.08986882978 rad

Height: ha = 24.80985462459
Height: hb = 24.80985462459
Height: hc = 23.9533079134

Median: ma = 24.82994180359
Median: mb = 24.82994180359
Median: mc = 23.9533079134

Inradius: r = 8.17222269987
Circumradius: R = 16.36553281404

Vertex coordinates: A[29; 0] B[0; 0] C[14.5; 23.9533079134]
Centroid: CG[14.5; 7.98443597113]
Coordinates of the circumscribed circle: U[14.5; 7.58877509936]
Coordinates of the inscribed circle: I[14.5; 8.17222269987]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 121.1898622333° = 121°11'19″ = 1.02664521779 rad
∠ B' = β' = 121.1898622333° = 121°11'19″ = 1.02664521779 rad
∠ C' = γ' = 117.6232755333° = 117°37'22″ = 1.08986882978 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.