[size=150]Given what you see here -- and without Googling -- create an equation that expresses the relationship among [br][br][b][i]C[/i], [math]\pi[/math], [/b]and [i][b]d[/b][/i], [br][br]where [b][i]C = [/i]circumference[/b] and [b][i]d[/i] = diameter [/b][/size]