# Objective
- Adds a basic `Extrusion<T: Primitive2d>` shape, suggestion of #10572
## Solution
- Adds `Measured2d` and `Measured3d` traits for getting the
perimeter/area or area/volume of shapes. This allows implementing
`.volume()` and `.area()` for all extrusions `Extrusion<T: Primitive2d +
Measured2d>` within `bevy_math`
- All existing perimeter, area and volume implementations for primitves
have been moved into implementations of `Measured2d` and `Measured3d`
- Shapes should be extruded along the Z-axis since an extrusion of depth
`0.` should be equivalent in everything but name to the base shape
## Caviats
- I am not sure about the naming. `Extrusion<T>` could also be
`Prism<T>` and the `MeasuredNd` could also be something like
`MeasuredPrimitiveNd`. If you have any other suggestions, please fell
free to share them :)
## Future work
This PR adds a basic `Extrusion` shape and does not implement a lot of
things you might want it to. Some of the future possibilities include:
- [ ] bounding for extrusions
- [ ] making extrusions work with gizmos
- [ ] meshing
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Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>