Free printable worksheets with answer keys. Pick a level, preview the questions, then open the sheet to swap or delete any single question.
Easy: Write the equation
A circle with center (h, k) and radius r has the equation (x − h)² + (y − k)² = r². The signs inside the brackets are the opposite of the center's coordinates, and the right side is the radius squared. From general form, group the x-terms and the y-terms and complete the square for each.
Write the equation, or find the center and radius.
Tip: tick “Step-by-step answer key” in the generator to print each step for marking.
The center is (3, −2): take the opposite of each number inside the brackets. The radius is √16 = 4, not 16.
x² + y² − 6x + 4y − 3 = 0 hides the center and radius. Completing the square in x and in y turns it back into standard form: (x − 3)² + (y + 2)² = 16.
Yes. Numbers are generated each time, and the answer key is calculated for that sheet. Swap any single question and its answer updates too.
Yes. In the generator, add more skills; each gets its own section on the sheet with its own instructions.
Yes. Generating and printing from the browser is free with no sign-up. PDF downloads need a free account.