What is the circumference is the the following circle r equals 1

 ok so if the radius of the circle is one all you need to doto find the diameter is multiply it by 2 becuase the diameter is twice the radius and the radius is half the diameter for instance..if you had a diameter of four the radiace would be two becuase half of four is two.So the formula to find the cicumfrance of a circle is C=2pirits basically just taking the radiace which in your case is one and multaplying it by two..ok so your like now i have two what do i do..?  Well thats it the answer is 2pi you would have to add the pi symbol <--- now if it has a number in replace of the pi say 3.14, alright your like i have two and i have 3.14 what do i do...you would just have to multiply the 2 by 3.14 to get an answer of....6.28!

Explanation: I hope this helps...:D

When a lake, river or other aquatic  system  becomes  eutrophic, it can have serious negative effects on other organisms like fish, birds and even people.if an algal bloom is so bad that it causes wide-spread death  in  the  water, the organisms that die will all sink to the bottom and start to decompose.

It's between the sagittarius and perseus arms of the milky way.