Which of the following is correct set notation?
(1,2,3)
1,2,3
{1,2,3}
none of the above

 The correct option is

(C) {1, 2, 3}.

Step-by-step explanation:  We are given to select the correct set notation from the following options :

Option (A) :  The given notation is (1, 2, 3).

Here, the elements are enclosed within first brackets, which is not used to write a set.

So, this option is NOT correct.

Option (B) :  The given notation is 1, 2, 3.

Here, the elements are not enclosed within any brackets. And, the elements of a set is always written within curly brackets.

So, this option is NOT correct.

Option (A) :  The given notation is {1, 2, 3}.

Here, the elements are enclosed within curly brackets, separated by comma. Since this method is used while writing a set, so, this option is CORRECT.

Thus, (C) is the correct option.

one of each metals

step-by-step explanation:

circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation: