A unit disk:

A disk sector:

An elliptical disk:

Differently styled unit disks:

Get the Area of a disk:

The area of an ellipse:

Create illusory contours:

Use a Disk to annotate a plot of a trig function:

Make a pie chart:

Archimedes' approximation of the circle area:

The square packing of disks:

The hexagonal packing of disks:

Simulation of elliptical gears:

An annulus is the RegionDifference of two disks with the same center:

Maximize the area of an ellipse of fixed perimeter:

As expected, the largest such ellipse is the circular disk:

Illustrate a function's radius of curvature:

By taking a RegionUnion of many disks, dilation of a mesh can be approximated:

Create disks of the dilation radius around the mesh boundary:

Then simply take the union of all disks plus the original mesh:

By removing a RegionUnion of many disks, erosion of a mesh can be approximated:

Create disks of the erosion radius around the mesh boundary:

Then subtract the union of the disks from the original mesh:

Use Rotate to get all possible elliptical disks:

The boundary of a disk defines a circle:

An implicit specification of a disk can be generated using RegionPlot:

A parametric specification of a disk can be generated using ParametricPlot:

Disk is a special case of Ball:

Disk is a special case of Ellipsoid:

ParametricRegion can represent any Disk:

ImplicitRegion can represent any Disk:

Disk is a norm ball for the Euclidean norm:

Using Scaled radii will depend on the PlotRange:

Using ImageScaled sizes will depend on the ImageSize and AspectRatio:

Random disk collections:

A family of disks:

Digital petals:

Yin and yang: