How do you solve this? Rhombus ABCD AC =16 BD =8. Find BC (radical). Its a hard one?

hmmm... I'm really rusty on this but unless I am mistaken... I have a rhombus with the left point being A, top being B, right being C and bottom being D. AC = 16. BC = 8. they intersect in the center and form 4 right triangles don't they? lets call the center E... so BE = 4 and EC = 8 and then it's just Pythagoreans theorem...