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Writing the Equation of a Circle - Printable Mathematics Worksheets - Wayground

Writing the Equation of a Circle

5 questions

9th - 11th Grade

Mathematics

Writing the Equation of a Circle is a free printable mathematics worksheet for students in Grades 9–11. It focuses on using the standard form of a circle’s equation to write an equation from a given center and radius, and to identify the center and radius from an equation. The five multiple-choice questions also require students to recognize that the radius is squared in the equation and interpret signs correctly when reading coordinates. This worksheet provides focused practice with the two-way relationship between a circle’s equation and its key features. Students select equations such as (x − h)² + (y − k)² = r², determine the radius by finding the square root of r², and identify the center from the signs inside each set of parentheses. It is suitable for guided practice, independent review, or a quick formative check, and includes a complete answer key for efficient checking.

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Worksheets

Writing the Equation of a Circle

Total questions: 5

Name
Class
Date
1.

Write the Equation to the circle with center of (2,5) and radius 6.

a)

(x-2)2 + (y-5)2= 6

b)

(x-2)2 + (y-5)2= 36

c)

(x+2)2 + (y-5)2= 6

d)

(x+2)2 + (y+5)2= 36

2.

State the coordinates of the center and the measure of the radius.

(x-1)2 + (y+5)2= 64

a)

Center (-1,5) Radius 8

b)

Center (-1,-5) Radius 64

c)

Center (1,-5) Radius 8

d)

Center (1,-5) Radius 64

3.
Write the equation of the circle.
a)
(x+1)2 + (y +1)2 = 3
b)
(x+1)2 + (y -1)2 = 3
c)
(x+1)2 + (y +1)2 = 9
d)
(x-1)2 + (y -1)2 = 9
4.
In the equation (x+2)2+(y-3)2=4, the radius of the circle is...
a)
4
b)
2
c)
3
d)
16
5.
In the equation (x-3)2+(y-2)2=16, the center of the circle is...
a)
(3,2)
b)
(-3, -2)
c)
(-2, -3)
d)
(2, 3)
Answer Key

Writing the Equation of a Circle

Total questions: 5

1.
b)

(x-2)2 + (y-5)2= 36

2.
c)

Center (1,-5) Radius 8

3.
c) (x+1)2 + (y +1)2 = 9
4.
b) 2
5.
a) (3,2)

FAQs

What does this worksheet cover?

This Grade 9–11 mathematics worksheet covers writing and interpreting the standard-form equation of a circle, (x − h)² + (y − k)² = r². Its five multiple-choice questions ask students to write an equation from a center and radius, identify a circle’s center and radius from its equation, and distinguish the radius from its squared value. Completing these items reinforces sign conventions and the relationship between the equation’s parts and the circle’s features.

How can I use this worksheet to teach writing the equation of a circle?

Introduce the standard form by labeling h, k, and r², then model how a center such as (2, 5) produces (x − 2)² + (y − 5)² and how a radius of 6 produces 36 on the right side. Next, have students complete the multiple-choice items while explaining why each distractor is incorrect, especially when a coordinate sign changes inside parentheses. Use the final questions as a short check that students can read the center and radius back from an equation.

What mistakes should I watch for when students complete this circle equation worksheet?

Watch for students reversing the signs of the center coordinates when reading expressions such as (x + 2)² or (y − 3)²; the signs inside the parentheses are opposite the center’s coordinates. Students may also write the radius instead of r², treating 64 as the radius rather than recognizing that the radius is 8, or confuse the center with the numbers’ order. Ask them to identify h, k, and r² before choosing an answer.

How do I assign and grade this worksheet?

This worksheet is available as a printable PDF and as a digital quiz on Wayground, so you can use the five multiple-choice circle-equation questions for classwork, homework, or a quick assessment. A complete answer key is included, and printable submissions can be graded by scanning student work with the Wayground for Teachers app. The printable option can also support schools that are reducing screen time.

How can I differentiate this circle equation worksheet for my students?

Use the worksheet’s Advanced Settings to adjust font size or spacing so the equation choices and coordinate notation are easier to read. You can also enable a dyslexia-friendly font or translate the worksheet into another language when that supports access to the five multiple-choice items. These changes preserve the focus on identifying centers and radii and writing circle equations.

Where can I find more worksheets like this on Wayground?

Wayground offers a comprehensive collection of free printable worksheets and practice problems across all subjects, including downloadable PDFs and answer keys to help students master essential skills and concepts. Browse more resources at https://wayground.com/en-us/worksheets.