Circles - Algebra Worksheet printable pdf download

Circles - Algebra Worksheet

Algebra 2

4.1 Notes

4.1 Circles

Date: ___________

Circle:

a set of points in a plane that are a fixed distance, called the ________________, from a given

point, called the __________________.

Learning Target A: I know the standard form for the equation of a circle.

The coordinate plane shows a circle with center C(h, k) and radius, r. P(x, y) is an arbitrary point on

the circle but is not directly above or below or to the left or right of C. A(x, k) is a point with the

same x-coordinate as P and the same y-coordinate as C. Explain why Δ�� is a right triangle.

Identify the lengths of the sides of Δ��. Remember that point P is arbitrary, so you cannot rely

upon the diagram to know whether the x-coordinate of P is greater than or less than h or whether

the y-coordinate is greater than or less than k, so you must use absolute value for lengths of the legs

of Δ��. Also, remember that the length of the hypotenuse of Δ�� is just the radius of the circle.

Length of segment AC = _________________

Length of segment AP = _________________

Length of segment CP = __________________

Apply the Pythagorean Theorem to Δ�� to obtain the equation of the circle.

Circles - Algebra Worksheet