Equation of a Circle

Equation of a circle

By Nicole Bush

Multiple Choice

Write the equation of the circle with a center at (2, –4)

and a radius of 4.

• (x – 2)² + (y + 4)² = 4

• (x + 2)² + (y – 4)² = 4

• (x – 2)² + (y + 4)² = 16

• (x + 2)² + (y – 4)² = 16

Multiple Choice

Write the equation of a circle with a center at (7, 0)

and a radius of 3.

• (x - ^7)^2 + y^2 = 9

• x^2 + (y -7)^2 = 9

• (x - 7)^2 + y^2 = 3

• x^2 + (y -7)^2 = 3

Multiple Choice

What is the center of this circle?

• (2, 2)

• (2, -2)

• (0, 0)

• (-2, 2)

Multiple Choice

What is the radius of this circle?

• 2

• 6

• 3

• 5

Multiple Choice

What is the equation of this circle?

• (x+2) + (y-2) = 9

• (x+2) + (y+2) = 9

• (x+1) + (y+1) = 3

• (x+1) + (y+1) = 3

​Did you get it right?

​Did you get it right?

Multiple Choice

$$\left(x+5\right)^2+\left(y-10\right)^2=169$$

Using the equation above, what is the center of the circle?

• (-5, 10)

• (5, -10)

• (5, 10)

• (-5, -10)

Math Response

$$\left(x+5\right)^2+\left(x-10\right)^2=169$$

Using the equation above, what is the radius?

Type answer here

Correct Answer: 13

Deg^°

Rad

Multiple Choice

What is the equation of the circle?

center: (5, 3), radius: 2

• $$\left(x-5\right)^2+\left(y-3\right)^2=2$$

• $$\left(x-5\right)^2+\left(y-3\right)^2=4$$

• $$\left(x+5\right)^2+\left(y+3\right)^2=2$$

• $$\left(x+5\right)^2+\left(y+3\right)^2=4$$

Multiple Choice

What is the equation of the circle?

center: (0, -3), radius: 5

• $$x^2+\left(y+3\right)^2=2.5$$

• $$x^2+\left(y-3\right)^2=5$$

• $$x^2+\left(y+3\right)^2=25$$

• $$x^2+\left(y-3\right)^2=25$$

Multiple Choice

What is the equation of the circle?

center: (4, 0), diameter: 6

• $$\left(x-4\right)^2+y^2=9$$

• $$\left(x+4\right)^2+y^2=9$$

• $$\left(x-4\right)^2+y^2=36$$

• $$\left(x+4\right)^2+y^2=36$$

Multiple Choice

What is the equation of a circle with radius 2 and center (3, 4)?

• (x+3)² + (y+4)² = 2
• (x-3)² + (y-4)² = 2
• (x+3)² + (y+4)² = 4
• (x-3)² + (y-4)² = 4

Multiple Choice

Write the standard form of the equation of the circle with radius of $$\sqrt[]{6}$$  and center at (8, 0).

• $$\left(x-8\right)^2+y^2=6$$  

• $$\left(x-8\right)^2+y^2=36$$  

• $$\left(x-8\right)^2+y=6$$  

• $$\left(x-8\right)^2+y^2=\sqrt[]{6}$$  

Multiple Choice

What is the standard equation of a circle whose center is at (-3,4) and the radius is 7?

• $$\left(x+3\right)^2+\left(y-4\right)^2=49$$  

• $$\left(x-3\right)^2+\left(y+4\right)^2=49$$  

• $$\left(x-3\right)^2+\left(y+4\right)^2=7$$  

• $$\left(x+3\right)^2+\left(y-4\right)^{2\ }=7$$  

Multiple Choice

What is the center-radius form of a circle with a radius of 12 and center at (-3, -5)?

• $$\left(x-3\right)^2+\left(x-5\right)^2=12$$  

• $$\left(x-3\right)^2+\left(y-5\right)^2=144$$  

• $$\left(x+3\right)^{2\ }+\left(x+5\right)^2=144$$  

• $$\left(x+3\right)^2+\left(y+5\right)^2=12$$  

Multiple Choice

What is the standard form of the equation of the circle whose center is at (5, 6) and the radius is 4?

• $$\left(x+5\right)^2+\left(x+6\right)^2=16$$  

• $$\left(x-5\right)^2+\left(y-6\right)^2=16$$  

• $$\left(x-5\right)^2+\left(y-6\right)^2=4$$  

• $$\left(x+5\right)^2+\left(x+6\right)^2=4$$