# 21 21 22 triangle

### Acute isosceles triangle.

Sides: a = 21   b = 21   c = 22

Area: T = 196.774398202
Perimeter: p = 64
Semiperimeter: s = 32

Angle ∠ A = α = 58.41218644948° = 58°24'43″ = 1.01994793577 rad
Angle ∠ B = β = 58.41218644948° = 58°24'43″ = 1.01994793577 rad
Angle ∠ C = γ = 63.17662710104° = 63°10'35″ = 1.10326339383 rad

Height: ha = 18.744037924
Height: hb = 18.744037924
Height: hc = 17.889854382

Median: ma = 18.76883243791
Median: mb = 18.76883243791
Median: mc = 17.889854382

Inradius: r = 6.14991869381
Circumradius: R = 12.3266324726

Vertex coordinates: A[22; 0] B[0; 0] C[11; 17.889854382]
Centroid: CG[11; 5.963284794]
Coordinates of the circumscribed circle: U[11; 5.5622219094]
Coordinates of the inscribed circle: I[11; 6.14991869381]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 121.5888135505° = 121°35'17″ = 1.01994793577 rad
∠ B' = β' = 121.5888135505° = 121°35'17″ = 1.01994793577 rad
∠ C' = γ' = 116.824372899° = 116°49'25″ = 1.10326339383 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.