Equation for Circle Geometry

• center (1,- 3) radius 1

• center (1,- 3) radius 9

• center (-1, 3) radius 3

• center (-1, 3) radius 1

A ceiling fan is pictured above. The tip of one of the fan blades is labeled point A.  Point A is 28 inches away from the center of the fan. About how far does point A on the fan travel when the fan blades make one full revolution?

• 28 inches

• 56 inches

• 176 inches

• 88 inches

(x-h)²+(y-k)²=r² is called....

• standard equation

• general equation

• extended equation

• symmetric equation

Choose the standard equation

• (x-5)²+(y-4)²=9

• (x+5)²+(y-4)²=9

• (x-5)²+(y+4)²=3

• (x-5)²+(y-4)²=3

Convert to standard form

x²+y²+8x-2y-8=0

• (x+4)²+(y-1)²=25

• (x-4)²+(y+1)²=25

• (x+4)²+(y-1)²=8

• (x-4)²+(y+1)²=8

(x-4)²+(y-3)²=12 has centre in...

• (4,3)

• (3,4)

• (-4,-3)

• (-4,3)

(x-4)²+(y-3)²=12 has radius of...

• 12

• 4

• 3

Would you say that this is the equation of a circle?

3x²+6x+3y²=27

• Yes

• No

What features can you obtain from: x²+y²=9

(Select all that apply)

• Centre in (0,0)

• Radius of 3

• Radius of 9

• Parabola

What features can you obtain from: 8(x+5)²+8(y-2)²=32

• Centre in (-5,2)

• Radius of 2

• Radius of 32

• Centre in (5,-2)