What’s on the The Equation of a Circle poster
The rule, 4 worked examples, and the mistake everyone makes.
- A circle with centre (h, k) and radius r has equation (x − h)² + (y − k)² = r².
- (x − h)² + (y − k)² = r²
- (x−2)² + (y+3)² = 25 = centre (2,−3), r = 5
- x² + y² = 9 = centre (0,0), r = 3
- r² = 25 = r = 5
- Expanded form = complete the square twice
- Common mistake: reading r as 25 → r = 5
It is the distance formula rearranged — every point exactly r from the centre.
Questions about the The Equation of a Circle poster
- What’s on the The Equation of a Circle poster?
- The rule, 4 worked examples, and the mistake everyone makes. A circle with centre (h, k) and radius r has equation (x − h)² + (y − k)² = r².; (x − h)² + (y − k)² = r²; (x−2)² + (y+3)² = 25 = centre (2,−3), r = 5; x² + y² = 9 = centre (0,0), r = 3; r² = 25 = r = 5; Expanded form = complete the square twice; Common mistake: reading r as 25 → r = 5. It is the distance formula rearranged — every point exactly r from the centre.
- Who is the The Equation of a Circle poster for?
- The Equation of a Circle is filed under 10th Grade (ages 15–16), so it matches what that year asks a child to remember. It is equally useful to an older student revisiting math, and to the parent or teacher answering the question at the kitchen table.
- When should you use the The Equation of a Circle poster?
- If it is not in standard form, complete the square in x and in y separately. A wall chart earns its place by being glanceable from where the work is happening, so The Equation of a Circle belongs on the wall where that math work actually happens, within glancing distance, rather than filed away.
- What other posters go with The Equation of a Circle?
- Sequences and Series, Circle Theorems and Completing the Square sit alongside The Equation of a Circle in the 10th Grade set. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Sequences and SeriesCircle TheoremsCompleting the Square
- Is the The Equation of a Circle poster free to download and print?
- Yes. The Equation of a Circle downloads as a free PDF with no account, no email and no watermark, like everything else in the 10th Grade set. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
- What size does the The Equation of a Circle poster print at?
- The Equation of a Circle is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of The Equation of a Circle loses nothing.Printing guide
Related posters
Charts that sit alongside The Equation of a Circle on the same wall.
Browse every 10th Grade poster, or start from the full catalogue.