# 21 22 22 triangle

### Acute isosceles triangle.

Sides: a = 21   b = 22   c = 22

Area: T = 202.9922456756
Perimeter: p = 65
Semiperimeter: s = 32.5

Angle ∠ A = α = 57.01548610187° = 57°53″ = 0.99550970473 rad
Angle ∠ B = β = 61.49325694906° = 61°29'33″ = 1.07332478031 rad
Angle ∠ C = γ = 61.49325694906° = 61°29'33″ = 1.07332478031 rad

Height: ha = 19.33326149292
Height: hb = 18.45438597051
Height: hc = 18.45438597051

Median: ma = 19.33326149292
Median: mb = 18.48797186126
Median: mc = 18.48797186126

Inradius: r = 6.24659217464
Circumradius: R = 12.51877065227

Vertex coordinates: A[22; 0] B[0; 0] C[10.02327272727; 18.45438597051]
Centroid: CG[10.67442424242; 6.15112865684]
Coordinates of the circumscribed circle: U[11; 5.97443599313]
Coordinates of the inscribed circle: I[10.5; 6.24659217464]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 122.9855138981° = 122°59'7″ = 0.99550970473 rad
∠ B' = β' = 118.5077430509° = 118°30'27″ = 1.07332478031 rad
∠ C' = γ' = 118.5077430509° = 118°30'27″ = 1.07332478031 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.