Circle Equations in Standard Form

Write the standard equation of the circle with the given center and radius; center (0, 0) and radius of 3.

• x² + y² = 4

• x² + y² = 81

• x² + y² = 9

• x² + y² = 3

What is the radius of the circle given by the equation (x - 7)² + (y + 3)² = 25?

• 3

• 5

• 10

• 25

A circle has the equation x² + y² - 12x + 8y + 3 = 0. Write the equation in standard form.

• (x - 6)² + (y + 4)² = 49

• (x + 4)² + (y - 6)² = 49

• (x - 6)² + (y + 4)² = 55

• x² + y² = 55

Change the following equation to standard form

• (x + 2)² + (y - 6)² = 48

• (x - 2)² + (y + 6)² = 48

• (x - 6)² + (y - 2)² = 48

• (x + 2)² + (y - 6)² = 48

The equation of a circle is x² + y² + 6x - 12y + 20 = 0. Write the equation in standard form.

• (x - 3)² + (y + 6)² = 25

• (x + 3)² + (y - 6)² = 25

• (x - 3)² + (y + 6)² = 45

• (x + 3)² + (y - 6)² = 5

A circle has the equation x² + y² + 10x - 4y + 20 = 0. Write it in standard form.

• (x - 5)² + (y + 2)² = 9

• (x + 5)² + (y - 2)² = 3

• (x + 5)² + (y - 2)² = 9

• (x - 5)² + (y + 2)² = 3

A circle has the equation x² + y² + 8x - 20 = 0. Write the equation in standard form.

• (x + 4)² + y² = 6

• (x + 4)² + y² = 36

• (x - 4)² + y² = 6

• (x - 4)² + y² = 36

A circle has the equation x² + y² - 6y - 5 = 0. Write the equation in standard form.

• x² + (y + 3)² = 7

• x² + (y - 3)² = 7

• x² + (y + 3)² = 14

• x² + (y - 3)² = 14

Write the equation of the circle with center C( -5 , 8 ) and radius = 7

• ( x - 5 )² + ( y + 8 )² = 14

• ( x - 5 )² + ( y - 8 )² = 49

• ( x - 5 )² + ( y + 8 )² = 49

• ( x + 5 )² + ( y - 8 )² = 49

What is the radius of the circle with this equation of (x - 5)² + (y + 7)² = 8?

• 4

• 8

• 4√2

• 2√2