Circles

Question 1

What is a Circle?

Answer 1

The set of points in a plane that are a fixed distance called the radius, from a fixed point, called the center. Because all of the points on a circle are the same distance from the center of the circle, you can use the Distance Formula to find the equation of a circle.

Question 2

What is the Radius of a Circle?

Answer 2

A fixed distance from the center that will reach any point in the circle.

Question 3

How do you find the equation of a Circle?

Answer 3

Using the Distance Formula.

Question 4

What is the formula for the equation of a Circle?

Answer 4

(x-h)^2+(y-k)^2=r^2. The Center is (h,k) and the Radius is r.

Question 5

What is the formula for Distance?

Answer 5

d=sqrt(((x2-x1)^2)+((y2-y1)^2)).

Question 6

What is the Tangent of a Circle?

Answer 6

A line in the same plane as the circle that intersects the circle at exactly one point. Recall from geometry that a Tangent to a Circle is Perpendicular to the radius at the point of tangency.

Question 7

How do you find the Tangent of a Circle?

Answer 7

You use the given point and draw a line Perpendicular to it. Once you draw your straight line, finding it’s equation is easy.