The flatworms, or Platyhelminthes, Plathelminthes, or platyhelminths (from the Greek ÏÎ»Î±ÏÏ, platy, meaning flat and á¼Î»Î¼Î¹Î½Ï (root: á¼Î»Î¼Î¹Î½Î¸-), helminth- , meaning worm) are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates.hey have about 11,000 species, more than all other platyhelminthes combined, and second only to roundworms among parasites on metazoans. Adults usually have two holdfasts, a ring around the mouth and a larger sucker midway along what would be the underside in a free-living flatworm.
square root. (MATHEMATICS) each positive number has another number that, when multiplied times itself, equals that number. So, for example, 4 has a square root of 2 (2 x 2 = 4). The square root of a negative number is an imaginary number. Imaginary numbers are not, by themselves, useful solutions to math problems; but they can be used to find them. BILL: Anna, we have a rectangle that's 3 x as long as it is wide, and it encloses an area of 300 square meters.
Consider the number you are calculating the square root of as the area S of a square. Because a square's area is L 2 where L is the length of one of its sides, therefore, by trying to find the square root of your number, you are trying to calculate the length L of the side of that square. As an example, let's find the square root of 45 using this method. 2  We know that 45 = 9 Ã 5 and we know that 9 = 3 Ã 3. 3  Thus, we can write our square root in terms of its factors like this: Sqrt(3 Ã 3 Ã 5). 4  Simply remove the 3's and put one 3 outside the square root to get your square root in simplest terms: (3)Sqrt(5).