My kids really struggle with identifying the base and height (altitude) of anything but the most “normal” triangle. In the Grade 6 OUR curriculum there is a pretty big focus on being able to do this. I’m wondering:
My experience is that you can get a lot done using points in the regular.
Here’s a thing that does a triangle with altitudes.
https://www.desmos.com/calculator/q1ejd1obnh
There’s a lot of room for a “what changes, what stays the same” type exploration with it, which will be determined by how you’re teaching it.
You can floow that with some drill type stuff, or use a sketch with a background of a triangle (without altitudes) and ask them to draw one in.
(Note - this would have been much easier to do if Desmos let you do math with points as if they were complex numbers. HINT HINT, With love)
One to one Teaching by Parents sitting next to them will help. They will learn a lot in personal experience.
Please be careful with equity issues.