This is a 29-page unit on graphing circles. Students will learn how to graph a circle by its equation. They will learn about horizontal and vertical shifts and how to find the radius. Students are shown through a tutorial how the equation is derived, explaining shifts along the way. Also, they will understand why the center of the circle has signs that are opposite those in the actual ( ) of the equation.
WS Circles1: Students graph 16 circles by their equations.
WS Circles2: Students graph another 16 circles. Then, they are given 8 circles and asked to derive the equation of them.
WS Circles Extension: These are tougher. Students are shown how to complete the square, then factor the resulting trinomial squares to write the equation of 6 circles and then make their graphs.
Puzzle #1: Students graph a number of circles. When finished, each circle will have a letter enclosed within it that can be used to answer a riddle.
Puzzle #2: Basic circles puzzle - used to review area and circumference.
Added 2/6/15: Two worksheets on creating the graphs of circles on TI-nspire calculators. The first one walks students through creating four circles (one in each quadrant). The second makes a snowman. This lesson is in a Word format, so you can make changes as needed for TI-84, etc.
Added 6/1/15: Enrichment activity #2. Students are given the coordinates of two endpoints of a diameter of a circle, then find the equation of a circle by using the distance formula and midpoint formula.
ALL activities have complete answer keys, made on computer for easy reading. In fact, the extension activity has all problems completed worked through to the answer, showing all steps.