# Objective
Working towards finishing a part of #10572, this PR adds a ton of math
helpers and useful constructors for primitive shapes. I also tried
fixing some naming inconsistencies.
## Solution
- Add mathematical helpers like `area`, `volume`, `perimeter`,
`RegularPolygon::inradius` and so on, trying to cover all core
mathematical properties of each shape
- Add some constructors like `Rectangle::from_corners`,
`Cuboid::from_corners` and `Plane3d::from_points`
I also derived `PartialEq` for the shapes where it's trivial. Primitives
like `Line2d` and `Segment2d` are not trivial because you could argue
that they would be equal if they had an opposite direction.
All mathematical methods have tests with reference values computed by
hand or with external tools.
## Todo
- [x] Add tests to verify that the values from mathematical helpers are
correct
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Co-authored-by: IQuick 143 <IQuick143cz@gmail.com>