Shape Architect Cheat Sheet
Shape Architect
Decomposition Cheat Sheet
Name: ____________________
Date: ____________________
The Blueprint Strategy
Irregular shapes are just rectangles in disguise! To find the area, decompose (slice) them into smaller rectangles that you can measure easily.
Construction Checklist
1
Slice
Draw a line to split the shape.
2
Label
Name pieces (A, B) to keep track.
3
Hunt
Find missing side lengths.
4
Area
Multiply L × W for each piece.
5
Total
Add all areas together.
Example
Blueprint Walkthrough
A 4 cm 9 cm
B 6 cm 3 cm
Rectangle A Area:
4 cm × 9 cm = 36 cm2
Rectangle B Area:
6 cm × 3 cm = 18 cm2
Total Combined Area:
36 + 18 = 54 cm2
The Vertical Rule
Parallel vertical sides must balance. If you're missing a small piece, subtract the short side from the total height.
The Horizontal Rule
Parallel horizontal sides must balance. The total width at the top must match the total width at the bottom.
Architect's Note: Always double-check your side-lengths before you multiply!
