 Circle Equation Practice Terms of Use    Contact Person: Donna Roberts  1.
Write the equation of a circle whose center is at (3,-2) and has a radius of 11. Choose:
 (x - 3)2 + (y - 2)2 = 121 (x - 3)2 + (y + 2)2 = 121 (x - 2)2 + (y + 3)2 = 121 (x + 2)2 + (y - 3)2 = 121

2.
Given the equation of a circle,
(x - 5)2 + (y + 3)2 = 196,
state the coordinates of the center and the radius. Choose:

3.
State the coordinates of the center and the radius of a circle whose equation is
x2 + y2 + 2x - 4y - 11 = 0 . Choose:
 center (-1,2), radius 4 center (-1,2), radius center (1,-2), radius center (1,-2), radius 4

 4 Graph the circle: x2 + 10x + y2 - 6y = - 30. 5.
Write the equation of a circle whose center is (-4,8) and passes through the point (-2,-1). Choose:
 (x - 4)2 + (y - 8)2 = 40 (x + 4)2 + (y - 8)2 = 85 (x + 2)2 + (y + 1)2 = 40 (x + 2)2 + (y + 1)2 = 85

 6 Write the general equation of a circle that is tangent to the x-axis, with a center located at (4,-6). 7 Show that the point lies on a circle whose center is the origin and contains the point (0,3). 8.
The equation x2 + y2 - 12x - 8y + 27 = 0 is equivalent to: Choose: (x - 6)2 + (y - 4)2 = 25 (x + 6)2 + (y + 4)2 = 25 (x - 6)2 + (y - 4)2 = 27 (x + 6)2 + (y + 4)2 = 9.
A regular hexagon ABCDEF with a side length of 4 units is centered at G(5,3). State the general equation of the circle circumscribing the hexagon. Choose:
 x2 + y2 - 10x - 6y + 30 = 0 x2 + y2 + 10x + 6y + 30 = 0 x2 + y2 - 10x - 6y + 18 = 0 x2 + y2 + 10x + 6y + 18 = 0

 10. Which of the equation choices could represent the circle shown on the graph? (Check all that apply, and hit SUBMIT!) (x - 5)2 + (y - 6)2 = 9 x2 + y2 = 9 x2 + y2 - 10x - 12y + 52 = 0 (x + 5)2 + (y - 6)2 = 9 x2 + y2 - 10x - 12y - 52 = 0 x2 + y2 = 10x + 12y x2 + y2 - 10x - 12y = -52 (Assume a radius of integer length.)

 11. The equation x2 + y2 - 6x + 4y = d describes a circle. a) Determine the y-coordinate of the center of the circle. b) The radius of the circle is 6 units. What is the value of "d" in the given equation. 12.
Given circle: x2 - 9x + y2 = 4.75
In center-radius form, this equation will be written as: Choose:
 (x + 3)2 + y2 = 25 (x - 4.5)2 + y2 = 25 (x - 3)2 + y2 = 20.25 (x +4.5)2+ y2 = 22.5625 