Fix triangle diagram typos and improve caption clarity

[aashu2006]

This PR fixes two errors in the triangle diagram alt text and improves the caption wording for clarity and accessibility in the variables-and-change tutorial.

Changes:

• Fix typo: "triangel" → "triangle"
• Fix incorrect coordinate in the example syntax: x1, y2 → x1, y1

This is a small, scoped documentation improvement with no changes to tutorial structure or examples.

[Divyansh013]

Could you please clarify as to exactly what typo you are referring here?

[aashu2006]

Thanks for checking!
The typos I am referring to are in the triangle diagram’s alt text in variables-and-change.mdx.
One was a small spelling error where triangel(...) was used instead of triangle(...), and the other was in the example syntax, where the first coordinate was written as x1, y2 instead of x1, y1.
I fixed both of those and also slightly simplified the caption wording to make it clearer.

[Divyansh013]

Hi, thanks for the clarification. I will recommend to just change the typo and keep the description intact.

[aashu2006]

Thanks for checking! @Divyansh013
I have updated the PR to only include the typo fixes and adjusted the description accordingly.

[Divyansh013]

LGTM!

cc @perminder-17 @ksen0 to merge