Query about Question 22 from "PrepSwift Quant Tickbox Quiz #12 (Geometry Column 3)"

https://www.gregmat.com/quizzes/quiz/prepswift-quant-tickbox-quiz-12-geometry-column-3 (Question 22)

Can someone help in visualising this + i can probably work with 60 degree, but what do i do in case of 10 degree

I even tried taking cos 10 and i know it would be more than cos 60, but even then I don’t understand how the inner square would rotate or its side length would change

help : /

Combine Square ABCD and the animation below for visualisation.

Square ABCD

ahh okay makes sense thanks : D