# 22 28 28 triangle

### Acute isosceles triangle.

Sides: a = 22   b = 28   c = 28

Area: T = 283.2376650171
Perimeter: p = 78
Semiperimeter: s = 39

Angle ∠ A = α = 46.26547927986° = 46°15'53″ = 0.80774729621 rad
Angle ∠ B = β = 66.86876036007° = 66°52'3″ = 1.16770598458 rad
Angle ∠ C = γ = 66.86876036007° = 66°52'3″ = 1.16770598458 rad

Height: ha = 25.74987863792
Height: hb = 20.23111892979
Height: hc = 20.23111892979

Median: ma = 25.74987863792
Median: mb = 20.92884495365
Median: mc = 20.92884495365

Inradius: r = 7.26224782095
Circumradius: R = 15.22440184927

Vertex coordinates: A[28; 0] B[0; 0] C[8.64328571429; 20.23111892979]
Centroid: CG[12.21442857143; 6.7443729766]
Coordinates of the circumscribed circle: U[14; 5.98108644078]
Coordinates of the inscribed circle: I[11; 7.26224782095]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 133.7355207201° = 133°44'7″ = 0.80774729621 rad
∠ B' = β' = 113.1322396399° = 113°7'57″ = 1.16770598458 rad
∠ C' = γ' = 113.1322396399° = 113°7'57″ = 1.16770598458 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.