Name: ________________________ Per: _______ Date: ___________ Geometry Honors
Conics: Circles
SWBAT: Write the equation of a circle from general form to standard form
Warm - Up
What is the center and radius of each of the following?
Equation
Center
Radius
a)
b)
c)
d)
e)
f)
“Conic Sections” are two-dimensional shapes that are formed when a cone is cut in different
ways. You are definitely familiar with a couple of them, although one or more of them might
be new to you.
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Name: ________________________ Per: _______ Date: ___________ Geometry Honors
A circle is a set of all points in a plane that are a fixed distance from a point called
its center. The fixed distance is the radius of the circle.
The standard form of an equation for a circle is (x – h)2 + (y – k)2 = r2
h represents ___________________
k represents ___________________
r represents ____________________
An equation which can be written in the following form (with constants D, E, F)
represents a circle:
x2 + y2 + Dx + Ey + F = 0
This is called the general form of the circle.
We can take an equation of a circle in standard form and put it in General Form
(x-4)2 + (y-1)2 = 9
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Name: ________________________ Per: _______ Date: ___________ Geometry Honors
Example 1:
Example 2:
Example 3:
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Name: ________________________ Per: _______ Date: ___________ Geometry Honors
SUMMARY
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Name: ________________________ Per: _______ Date: ___________ Geometry Honors
Homework
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Name: ________________________ Per: _______ Date: ___________ Geometry Honors
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