I'm hoping someone can help with this one, I'm not sure why I'm not seeing it . I've attached a picture from my text book and an answer I've found but don't quite understand.
An equilateral triangle where each side's length equals x is inscribed in a circle of radius r. Show that:
An answer I've found already but don't understand:
. Solve for rē and you'll get:
However, I'm not sure how one is supposed to know that everything else made sense though...