Skip to content
Home › Geometry Math › Geometry Worksheets › Equation of a Circle Worksheet with Answers – Geometry (Free PDF)

Equation of a Circle Worksheet with Answers – Geometry (Free PDF)

Last updated: October 22, 2026 · Written by the Math Made Easy math teachers

Geometry Math Worksheets – Mathbot, the Math Made Easy robot coach, with free printable worksheets for Geometry

Looking for an equation of a circle worksheet with answers PDF? Then this Geometry worksheet on Writing and Graphing Circle Equations gives problems ranked from easy to hard. These problems build the equation of a circle from the Pythagorean Theorem, read centers and radii, complete the square, and classify points (G-GPE.A.1). Early problems use standard form; later problems start from general form. Cell towers, Ferris wheels and plazas supply the contexts.

Standards: G-GPE.A.1 · Level: Grade 10 Geometry

Problem 2 Centered at the Origin ★★★

A radar screen is centered at the origin. One range ring has radius 11 units. Write its equation.

Problem 3 Read Center and Radius ★★★

−11−9−7−5−3−11357−17−15−13−11−9−7−5−3−11xy
Graph of (x + 2)² + (y + 8)² = 64.

State the center and the radius of the circle (x + 2)² + (y + 8)² = 64.

Problem 4 Center on the x-Axis ★★★

A circle has center (−5, 0) and radius √10. Write its equation.

Problem 5 Equation from a Graph ★★★

−3−2−11234567−4−3−2−1123456xy(2, 1)(6, 1)
Circle on the coordinate plane.

Write the equation of the circle shown.

Problem 6 Radius from a Point ★★★

A circular skating rink is centered at (−3, 2) on a grid, and a light pole at (1, 7) stands exactly on its edge. Write the equation of the rink.

Problem 7 Equation from a Diameter ★★★

The endpoints of a diameter are (−4, 3) and (6, −1). Write the equation of the circle.

Problem 8 Inside, On or Outside ★★★

−7−5−3−113579−10−8−6−4−2246xy(1, −2)abc
Points a, b and c relative to the circle.

Circle C: (x − 1)² + (y + 2)² = 40. Decide whether each point is inside, on or outside: (a) (7, 0) (b) (−2, 3) (c) (5, 4).

Problem 9 Another Point on the Circle ★★★

A circle has center (−2, −4) and passes through (6, −1). Use the Pythagorean Theorem or the circle equation to show that (1, 4) is also on the circle.

Problem 10 Complete the Square: Basic ★★★

Rewrite x² + y² − 6x + 10y + 18 = 0 in standard form. Give the center and radius.

Problem 11 Complete the Square: Irrational Radius ★★★

Rewrite x² + y² + 8x − 2y − 4 = 0 in standard form. Give the center and the radius.

Problem 12 Completing the Square with Large Terms ★★★

Rewrite x² + y² − 12x − 4y + 20 = 0 in standard form. Give the center and the radius in simplest radical form.

Problem 13 Divide First ★★★

Rewrite 2x² + 2y² + 4x − 16y − 10 = 0 in standard form. Find the center and radius.

Problem 14 Circle, Point or Nothing? ★★★

Complete the square for each equation and say whether it is a circle, a single point or has no graph. (a) x² + y² − 4x + 6y + 13 = 0 (b) x² + y² − 4x + 6y + 20 = 0

Problem 15 Cell Tower Coverage ★★★

On a county map with 1 unit = 1 mile, a cell tower at (−3, 5) reaches 12 miles in every direction. (a) Write the equation of the edge of its coverage. (b) A town sits at (6, −3). Is it covered?

Problem 16 Flower Bed in a Corner ★★★

A circular flower bed with radius 4 feet fits in the corner formed by two perpendicular fences along the positive x-axis and y-axis, touching both fences. Write the equation of its edge.

Problem 17 Circle Through Three Points ★★★

A circular plaza passes through the points (0, 0), (10, 0) and (0, 4) on a city grid. Find the equation of the circle. (Hint: the angle at the origin is a right angle.)

Problem 18 Ferris Wheel Heights ★★★

A Ferris wheel has radius 10 feet and its center is 12 feet above the ground, directly above the origin of a coordinate system. (a) Write the equation of the wheel. (b) A rider is 5 feet to the right of the center line. How high above the ground can the rider be? Round to the nearest tenth.

Problem 19 Bike Path Through a Plaza ★★★

A circular plaza has equation (x − 1)² + (y − 2)² = 8 and a straight bike path follows y = x + 1. Find the two points where the path meets the edge of the plaza.

Problem 20 Tangent Line to a Circle ★★★

The point (3, 4) lies on the circle (x + 1)² + (y − 2)² = 20. (a) Verify this. (b) Find the equation of the tangent line to the circle at (3, 4).

View the Equation Of A Circle worksheet answer key

Mis à jour le