Annie visits a redwood forest. She is amazed to read that a certain
tree trunk has a diameter of 25 feet. What is the approximate
circumference of this tree's trunk?
To find circumference, you multiply the diameter of the circle by pi. Pi is 3.14 and the diameter is 25 feet. 25×3.14 is 78.5. The circumference of this tree’s trunk is 78.5 feet.