What’s on the Area of a Circle poster
The rule, 4 worked examples, and the mistake everyone makes.
- The area of a circle is pi times the radius squared. The radius is squared, not the d…
- A = πr²
- r = 3 = A ≈ 28.3
- d = 10, so r = 5 = A ≈ 78.5
- A = 50.24, find r = r = 4
- Double the radius = area × 4
- Common mistake: A = πd² → A = πr²
Circumference uses r once, so units are cm. Area uses r twice, so units are cm².
Questions about the Area of a Circle poster
- What’s on the Area of a Circle poster?
- The rule, 4 worked examples, and the mistake everyone makes. The area of a circle is pi times the radius squared. The radius is squared, not the d…; A = πr²; r = 3 = A ≈ 28.3; d = 10, so r = 5 = A ≈ 78.5; A = 50.24, find r = r = 4; Double the radius = area × 4; Common mistake: A = πd² → A = πr². Circumference uses r once, so units are cm. Area uses r twice, so units are cm².
- Who is the Area of a Circle poster for?
- Area of a Circle is filed under 7th Grade (ages 12–13), 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 Area of a Circle poster?
- Write r = … before anything else. Halving the diameter is the step people skip. A wall chart earns its place by being glanceable from where the work is happening, so Area 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 Area of a Circle?
- Angle Pairs, Box Plots and Circles, Angles & Volume sit alongside Area of a Circle in the 7th Grade set. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Angle PairsBox PlotsCircles, Angles & Volume
- Is the Area of a Circle poster free to download and print?
- Yes. Area of a Circle downloads as a free PDF with no account, no email and no watermark, like everything else in the 7th 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 Area of a Circle poster print at?
- Area 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 Area of a Circle loses nothing.Printing guide
Related posters
Charts that sit alongside Area of a Circle on the same wall.
Browse every 7th Grade poster, or start from the full catalogue.