Answer & Step-by-step explanation:
[tex]\frac{c}{a}[/tex] is the same as [tex]\frac{a}{d}[/tex] . This is because the letter c in the small triangle is in the same positions as a in the biggest triangle, and a in the little is in the same position as d in the big one.
If it's confusing, let me know (I'm not very good with words lol)
