High school (grades 11–12) · TypeLab 2D
Tunnel Lining Cross Section
Tunnel Lining Cross Section: a composite plane figure made of a rectangle 7.2 × 3.6 cm, joined with a semicircle of radius 3.6 cm, minus a rectangle 5.2 × 3.6 cm, minus a semicircle of radius 2.6 cm. It is a classic high school (grades 11–12) geometry problem (“Calculus & Optimization”). The net area is 16.93 cm² and the total perimeter is 35.87 cm.
Certified measurements (1:1 scale)
- Net area
- 16.93 cm²
- Total perimeter
- 35.87 cm
- Bounding box
- 7.2 × 7.2 cm
- Basic shapes
- 4
Step-by-step decomposition
- 1.Baserectangle 7.2 × 3.6 cm25.92 cm²
- 2.+semicircle of radius 3.6 cm20.36 cm²
- 3.−rectangle 5.2 × 3.6 cm18.72 cm²
- 4.−semicircle of radius 2.6 cm10.62 cm²
Area of each basic shape before the Boolean composition.
How to find the area
Area formula: A_cls = (B·H + ½πR²) − (b·H + ½πr²)
Split the figure into basic shapes, find each area, add the joined parts and subtract the cut-outs: A = 25.92 + 20.36 − 18.72 − 10.62 = 16.93 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.
