[tex]\huge{\boxed{168 \pi}}[/tex]
To find the circumference of a circle when you know its radius, use [tex]2 \pi d[/tex], where [tex]d[/tex] is the diameter.
Substitute in the radius of 84. [tex]2 * \pi * 84[/tex]
Multiply the constants. [tex]\boxed{168 \pi}[/tex]
