Middle school · TypeLab 2D
Decomposed Isosceles Trapezoid
Decomposed Isosceles Trapezoid: a composite plane figure made of a rectangle 4.2 × 4 cm, joined with a triangle with base 4 cm and height 2.2 cm, joined with a triangle with base 4 cm and height 2.2 cm. It is a classic middle school geometry problem (“Composite Polygons”). The net area is 25.6 cm² and the total perimeter is 21.93 cm.
Certified measurements (1:1 scale)
- Net area
- 25.6 cm²
- Total perimeter
- 21.93 cm
- Bounding box
- 8.6 × 4 cm
- Basic shapes
- 3
Step-by-step decomposition
- 1.Baserectangle 4.2 × 4 cm16.8 cm²
- 2.+triangle with base 4 cm and height 2.2 cm4.4 cm²
- 3.+triangle with base 4 cm and height 2.2 cm4.4 cm²
Area of each basic shape before the Boolean composition.
How to find the area
Area formula: A = b·h + 2·(½·p·h)
Split the figure into basic shapes, find each area, add the joined parts and subtract the cut-outs: A = 16.8 + 4.4 + 4.4 = 25.6 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.
