by Dave Youngs and Michelle Pauls
Puzzle Topic
Spatial-relationship skills.
Puzzle Question
How can you move a given number of toothpicks to create eight triangles
or seven quadrilaterals from the arrow shape?
Materials
Student sheet
Flat toothpicks, 16 per student
Puzzle Background
This particular puzzle, like Nine-Square Toothpick Challenge, comes
from The Moscow Puzzles. The puzzle is found in the section entitled
"Geometry with Matches," which offers a selection of matchstick puzzles
as "geometrical amusements that sharpen your mind." Arrow Arrangements
is one of the more difficult puzzles in this section, and requires students
to understand and apply some basic geometric terms such as congruent, triangle,
and quadrilateral. Thus it has the benefit of not only sharpening
the mind, but also giving some practice thinking about geometric shapes and
concepts.
Puzzle Presentation
1. Students will each need a copy of the student sheet
and 16 flat toothpicks to complete this puzzle.
2. Be sure students understand the concept of congruent triangles and quadrilaterals
before they begin.
Solution Hint
Work backwards, starting with the correct number of triangles or quadrilaterals,
and try to make the arrow from that arrangement.