Circle Equation Standard

A circle has an equation of x² + y² = 81. What is the center of a circle?

• A. (0, 0)

• B. (1, 1)

• C. (1, 0)

• D. (0, 1)

What is the general form of the equation (𝑥 − 2) 2 + (𝑦 + 5) 2 = 9?

• 𝑥 2 + 𝑦 2 + 6𝑥 − 8𝑦 + 12 = 0

• 𝑥 2 + 𝑦 2 − 4𝑥 + 10𝑦 + 20 = 0

• 𝑥 2 + 𝑦 2 + 7𝑥 − 8𝑦 + 15 = 0

• 𝑥 2 + 𝑦 2 + 3𝑥 − 2𝑦 − 4 = 0

What is the radius of the equation of the circle 𝑥 2 + 𝑦 2 + 4𝑥 − 4𝑦 − 28 = 0?

• A. 36

• B. 4

• C. 28

• D. 6

Find the general form of the equation of the circle 𝑥 2 + (𝑦 − 5) 2 = 36

• 𝑥 2 + 𝑦 2 + 𝑥 − 10𝑦 − 9 = 0

• 𝑥 2 + 𝑦 2 + 𝑥 + 10𝑦 − 9 = 0

• 𝑥 2 + 𝑦 2 − 10𝑦 − 9 = 0

• 𝑥 2 + 10𝑦 − 9 = 0

What is the equation of the circle. 

• (x - 3)²  + (y + 4)² = 9

• (x - 3)²  + (y + 4)² = 3

• (x)²  + (y)² = 9

• (x - 7)²  + (y + 1)² = 16

The diameter of a circle has length 12. The center is at (-5, 2). Give the equation of the circle.

• (x - 2)² + (y + 5)² = 36

• (x - 5)² + (y + 2)² = 6

• (x + 5)² + (y - 2)² = 36

• (x + 2)² + (y - 5)² = 6

Based on the graph, what is the standard equation of the circle?

In the equation (x-3)²+(y-2)²=16, the center of the circle is...

• (3,2)

• (-3, -2)

• (-2, -3)

• (2, 3)

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

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

• 3

• 5

• 10

• 25