Middle school · TypeLab 2D
Five-Petal Rosette
Five-Petal Rosette: a composite plane figure made of a regular pentagon with side 3 cm, joined with a semicircle of radius 1.5 cm, joined with a semicircle of radius 1.5 cm, joined with a semicircle of radius 1.5 cm, joined with a semicircle of radius 1.5 cm, joined with a semicircle of radius 1.5 cm, minus a circle of radius 0.9 cm. It is a classic middle school geometry problem (“Arcs & Semicircles”). The net area is 30.6 cm² and the total perimeter is 29.21 cm, including 5.65 cm along the inner hole.
Certified measurements (1:1 scale)
- Net area
- 30.6 cm²
- Total perimeter
- 29.21 cm
- Outer boundary
- 23.56 cm
- Hole boundaries
- 5.65 cm
- Bounding box
- 6.93 × 6.73 cm
- Basic shapes
- 7
Step-by-step decomposition
- 1.Baseregular pentagon with side 3 cm15.48 cm²
- 2.+semicircle of radius 1.5 cm3.53 cm²
- 3.+semicircle of radius 1.5 cm3.53 cm²
- 4.+semicircle of radius 1.5 cm3.53 cm²
- 5.+semicircle of radius 1.5 cm3.53 cm²
- 6.+semicircle of radius 1.5 cm3.53 cm²
- 7.−circle of radius 0.9 cm2.54 cm²
Area of each basic shape before the Boolean composition.
How to find the area
Area formula: A = A_pent + 5·(½·π·r²) − π·r₀²
Split the figure into basic shapes, find each area, add the joined parts and subtract the cut-outs: A = 15.48 + 3.53 + 3.53 + 3.53 + 3.53 + 3.53 − 2.54 = 30.6 cm².
Editable in PowerPoint & Office
The .PPTX file contains native DrawingML shapes: outlines, dimensions and labels stay separate objects you can recolor and edit in PowerPoint, Keynote and Google Slides. The .SVG file is pure vector art at 1:1 scale on an A4 sheet, ready for print, LaTeX and textbook layout.
