Firefly Fence
Stretch your glowing fence until its perimeter, 2 × (width + height) in cm, matches the moth's sign — then snap it shut to trap the moth.
🎯 Read the moth's target, change it to cm in your head, build a fence with that perimeter, and press Snap Shut.
✓ Solved!
The perimeter is the length all the way around the fence:
2 × (width + height). The moth's sign shows the same length in a
different unit — 1 m = 100 cm and 1 cm = 10 mm —
so turn its number into cm before you build. Grab the bright
corner to stretch the fence, or nudge the sliders.
← Back to M3.1 Perimeter & unit conversion