Euclidean Geometry in Physics I've started tutoring my 13 year old niece in math.  She learning geometry this year (it's a year-round school).  Obviously, it'll just be basic Euclidean geometry -- though I might try to get to a little non-Euclidean stuff at the end.
Anyway, she says she's interested in physics (how she can interested in something she's never studied IDK, but I guess it's good she's interested in science).  I was trying to think up ways to teach her some physics principles through geometry.  Unfortunately, without calculus, the only physics I can think of that uses geometry is the center of mass of an object.
Are there any other physics principles/ problems I could go over if all she knows is some basic algebra and geometry?

A few thoughts:


*

*Resolving vectors into components is all about trigonometric ratios, which in turn are all about similar triangles.

*Inverse-square laws (gravity, electrical force) can be interpreted geometrically in terms of the surface area of a sphere.

*Planetary orbits and ellipses.


I am sure I will think of more and will add to this list as they occur to me.
