Equation of a Circle

Which of the following is the equation of a circle with a center at (-1,3) and a radius of 4?

• (x-1)²+(y+3)²=4

• (x-1)²+(y+3)²=16

• (x+1)²+(y-3)²=4

• (x+1)²+(y-3)²=16

Which circle has a center at (-3,-6) and passes through the point (-4,8)?

• (x-3)²+(y-6)²=197

• (x+3)²+(y+6)²=197

• (x-3)²+(y-6)²=32

• (x+3)²+(y+6)²=32

• (x+7)²+(y-4)²=18

• (x-7)²+(y+4)²=324

• (x+7)²+(y-4)²=324

• (x+7)²+(y-4)²=81

• (x-7)²+(y+4)²=81

• (x+2)²+(y+8)²=25

• (x-2)²+(y-8)²=10

• (x+2)²+(y+8)²=10

• (x+2)²+(y+8)²=100

• (x-2)²+(y-8)²=100

• (x-3)²-(y+1)²=8

• (x-3)²+(y+1)²=8

• (x+3)²+(y-1)²=16

• (x-3)²-(y+1)²=16

• (x-3)²+(y+1)²=16

In the equation (x+2)²+(y-3)²=4, the radius of the circle is...

• 4
• 2
• 3
• 16

In the equation (x-4)²+(x-3)²=25, the radius is

• 4
• 3
• 5
• 25

A line segment between two points on the circle which passes through the center

• Radius
• Diameter
• Chord
• Tangent

Circles with exactly the same radius measures

• Similar Circles
• Concentric Circles
• Congruent Circles
• Semicircle

The distance around a circle

• Diameter
• Radius
• Circumference
• Area