High school (grades 9–10) · TypeLab 2D
Hollow Rectangular Section
Hollow Rectangular Section: a composite plane figure made of a rectangle 6.4 × 8 cm, minus a rectangle 4 × 5.6 cm. It is a classic high school (grades 9–10) geometry problem (“Structural Sections”). The net area is 28.8 cm² and the total perimeter is 48 cm, including 19.2 cm along the inner hole.
Certified measurements (1:1 scale)
- Net area
- 28.8 cm²
- Total perimeter
- 48 cm
- Outer boundary
- 28.8 cm
- Hole boundaries
- 19.2 cm
- Bounding box
- 6.4 × 8 cm
- Basic shapes
- 2
Step-by-step decomposition
- 1.Baserectangle 6.4 × 8 cm51.2 cm²
- 2.−rectangle 4 × 5.6 cm22.4 cm²
Area of each basic shape before the Boolean composition.
How to find the area
Area formula: A = B·H − (B−2s)·(H−2s)
Split the figure into basic shapes, find each area, add the joined parts and subtract the cut-outs: A = 51.2 − 22.4 = 28.8 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.
