TYPEMATH
C026 · Composite PolygonsISO 128 · 1:1
Chamfered Square Octagon — composite figure at 1:1 scale with dimensions, area 38.24 cm²
A = L² − 2·c²

Middle school · TypeLab 2D

Chamfered Square Octagon

Chamfered Square Octagon: a composite plane figure made of a square with side 6.8 cm, minus a square with side 2.83 cm, minus a square with side 2.83 cm, minus a square with side 2.83 cm, minus a square with side 2.83 cm. It is a classic middle school geometry problem (“Composite Polygons”). The net area is 38.24 cm² and the total perimeter is 22.51 cm.

Certified measurements (1:1 scale)

Net area
38.24 cm²
Total perimeter
22.51 cm
Bounding box
6.8 × 6.8 cm
Basic shapes
5
Open in TypeLab 2D

Step-by-step decomposition

  1. 1.Basesquare with side 6.8 cm46.24 cm²
  2. 2.−square with side 2.83 cm8 cm²
  3. 3.−square with side 2.83 cm8 cm²
  4. 4.−square with side 2.83 cm8 cm²
  5. 5.−square with side 2.83 cm8 cm²

Area of each basic shape before the Boolean composition.

How to find the area

Area formula: A = L² − 2·c²

The parts overlap or intersect, so the net area (38.24 cm²) comes from the exact Boolean operation rather than from a plain sum of the part areas.

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.

Composite figures →