🧩 Ceardlann Tangram (The 7 Ancient Tans)
Arrange the 7 geometric pieces (triangles, square, parallelogram) to form silhouettes without overlapping!
Selected Tan Controls
💡 Tip on Interactive Whiteboard: Tap a piece to select, drag with one finger, and tap the rotation buttons to align.
Did You Know? · An Raibh Fhios Agat?
A Tangram originated in China (called Qiqiaoban, meaning "seven boards of skill") and came to Europe in the early 1800s.
- 🔺 2 Large Triangles (each 1/4 of total area)
- 🔺 1 Medium Triangle (1/8 of total area)
- 🔺 2 Small Triangles (each 1/16 of area)
- ⬛ 1 Square (1/8 of area)
- 🔷 1 Parallelogram (1/8 of area)
🔷 Saotharlann Teascailithe (Tessellation Lab)
Tessellation is tiling a surface using geometric shapes without gaps or overlapping. Explore why only certain regular shapes tessellate alone!
Equilateral Triangles
Because 360° divided by 60° equals exactly 6, exactly six equilateral triangles fit snugly around every corner point without overlapping or leaving any gaps!
🌿 Nature & Real World Examples
🪞 Stiúideo Siméadrachta (Symmetry Mirror Studio)
Draw on one side and watch lines of reflective symmetry paint in real-time!
Lines of Symmetry in 2D Shapes
☘️ Celtic Art & High Crosses
Ancient Irish Celtic high crosses and illuminated manuscripts like the Book of Kells use both reflective and rotational symmetry to craft intricate knotwork.