The equilateral triangle shown is rotated about line a. Each What shape is created by the rotation and what is the side of the triangle measures 20 mm. approximate circumference of the base? Circumference of a circle: C = 2tr a cylinder with a circumference of about 63 mm a cylinder with a circumference of about 126 mm a cone with a base circumference of about 63 mm a cone with a base circumference of about 126 mm It's B >> a cylinder with a circumference of about 126 mm ÷)​