Circles centred at the origin: x² + y² = r²

Questions at easy, medium and hard levels. Pick a level and get a fresh set every time, with instant feedback.

Learn it A circle with centre (0, 0) and radius r has equation x² + y² = r². A point is on the circle if x² + y² = r², inside if it is less, and outside if it is more.

Example: Is (3, −5) inside, on or outside x² + y² = 36?

3² + (−5)² = 9 + 25 = 34.
34 < 36, so it is inside.

Loading questions…