Area is the space inside.
Imagine covering the floor with square tiles. Each tile covers 1 square unit. Count the tiles: 4 × 3 = 12 square units.
We write square units as units², cm² or m².
GEOMETRY / A HANDS-ON ADVENTURE
Inside the shape.
Around the edge.
Build it. Stretch it. Count it. Discover how area and perimeter
tell two different stories about the same shape.
■ Area: space inside━ Perimeter: distance around
0 of 3 explorer missions discovered0 / 3 mission stars
01 / BEGINNER
Cover it or go around it?
Perimeter is the distance around.
Imagine walking around the edge. Add all four sides: 4 + 3 + 4 + 3 = 14 units.
We measure distance in units, cm or m.
02 / EXPLORER
What changes when you stretch it?
Each little square is 1 unit wide and 1 unit tall.
Try this discovery
Can you create two different rectangles with an area of 24 square units? Do they have the same perimeter?
Save two different arrangements to compare them.
03 / EXPLORER → MASTER
Your tiles. Your rules. Your discovery.
Tap to fill or remove. Drag to draw or erase a whole trail.
Keyboard: Tab to the board, use arrow keys to move, and Space or Enter to toggle a tile. On touch screens, draw inside the board; scroll using the space around it.
Make something unexpected.
Blue squares count towards area. Orange edges count towards perimeter. Shared edges disappear from the boundary. Corners touching diagonally do not share an edge.
Separate islands and holes are welcome. Every exposed edge counts, including edges around a hole.
MASTER MISSION / ★ 1 STAR
Build a shape with…
Need a hint?
Start with a 3 × 4 rectangle. It has area 12 and perimeter 14. Can you move a corner tile somewhere else to create four more exposed edges?
One possible solution
Remove a corner from the 3 × 4 rectangle. Put that tile on an empty square away from the rectangle, touching no other tile. Area stays 12; perimeter becomes 18.
04 / EXPLORER
24 tiles. Four very different fences.
Use every tile. Pick an arrangement to see its shape.
Predict before you reveal
Which arrangement do you think has the smallest perimeter?
05 / MASTER
A little fence. A big possibility.
You have 24 metres of fencing. Build the largest possible rectangular garden.
THE GARDEN PLANNERFence budget: 24 m
Try long and thin, then shorter and wider. Using all the fencing does not always give the biggest area.
Give me a hint
If all 24 metres are used, length + width = 12. Compare the areas of pairs of whole numbers that add to 12.
The largest garden is 6 m × 6 m: area 36 m², perimeter 24 m. Whole-number pairs adding to 12 give areas 11, 20, 27, 32, 35 and 36 m². Moving the sides closer together increases the area, with a square giving the most.
06 / PRACTICE & ASSESSMENT
Make your understanding stick.
Three levels, four questions each. Hints are always welcome.
Mission stars and practice scores are separate. Your activity and quiz progress can be saved on this device. Manage it in My Progress.