OpenOlympiad
Concept 11 of 19Foundation
Video

Shape, matchstick & figure-counting patterns

Patterns with shapes ask you to count sticks, dots, corners, or squares. Strategy:

  1. Count for the first few figures.
  2. Look at the difference — is it arithmetic?
  3. Write a formula in n.

Matchstick patterns:

  • Row of linked triangles: 1→3, 2→5, 3→7 sticks → 2n + 1.
  • Row of linked squares: 1→4, 2→7, 3→10 sticks → 3n + 1.
  • Row of hexagons joined side-by-side: 1→6, 2→11, 3→16 → 5n + 1.
Example
10 matchstick triangles joined in a row use 2·10 + 1 = 21 sticks.
💡 Tip:The FIRST figure uses base sticks; each added figure adds (sides − shared) sticks.
Prefer a video? Open YouTube search for “matchstick pattern formula class 6

🎯 Try it!

5 questions to check what you just read.

0 / 5
  1. Q1.5 linked triangles in a row (2n+1 sticks). Sticks?
  2. Q2.6 linked squares in a row (3n+1 sticks). Sticks?
  3. Q3.Dots in 8th square-dot figure?
  4. Q4.8 hexagons joined in a row (5n+1 sticks). Sticks?
  5. Q5.Extra dots added going from 5th to 6th triangular figure?