The standard form of the equation of a circle is 

,

where the center is  and the radius is . 

The center of the circle is the origin, so .

The equation will be

for some .

The circumference of the circle is , so

The equation is , which is not among the responses.

To get to , move right along the x-axis by , then move up on the y-axis by .

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis.

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis.

To get to , move left on the x-axis by , then move up on the y-axis by .

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis.

To get to , only move up by  on the y-axis. Do not move along the x-axis because the x-coordinate is .

To get to , move right on the x-axis by  then move up on the y-axis by .

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis.

To get to , move left on the x-axis by  then move down the y-axis by .

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis.

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis.

To get to , move right on the x-axis by , then move down on the y-axis by .

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis.

To get to , move right on the x-axis by  then move down on the y-axis by .

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis. The first term in the ordered pair is the movement in the x direction and the second point is the movement in the y direction.

To get to , move left on the x-axis by , then move up on the y-axis by .

To get to , move left on the x-axis by , then down on the y-axis by .

The sign in front of each number represents which direction to go on the x or y-axis starting at the origin . If the number is positive you go right on the x-axis or up on the y-axis. If the sign is negative then you move to the left on the x-axis or down on the y-axis. The first term in the ordered pair is the movement in the x direction and the second point is the movement in the y direction.