they have cell walls made of cellulose, whereas fungi have cell walls made of chitin. Like other protists, they have complicated life cycles with both asexual and sexual reproduction. They are motile cells during some stages of their life cycle.
The area of a circle is Pi times the diameter. So depending on what Pi equals in this problem it could be one of two answers If Pi is not a number it's just 30 Pi If the number is 3.14 then the number is 94.2 Hope this helps