Mathematics Knowledge

What is the circumference of a circle if the radius is 4?

As an ASVAB tutor, I remind my students of the importance of knowing all the formulas for area, circumference, volume, and surface area.  Geometry is found on the Mathematics Knowledge section of the ASVAB.  In my book, The ASVAB Tutor’s Mathematics Knowledge Study Guide, I present all the formulas for the shapes that can appear on the Mathematics Knowledge section of the ASVAB.  Today’s question asks about the circumference of a circle.  Do you know the formula for circumference of a circle?  I will present the answer and explanation tomorrow.