To find the perimeter, we count the number of tile edges that make up the border of each shape. Let’s go one by one.
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First Shape (Top Rectangle):
It’s a rectangle that is 6 tiles wide and 4 tiles tall.
Perimeter = top + bottom + left side + right side
= 6 + 6 + 4 + 4
=
20
✔ Check: Counting around the edge — yes, 20 tile sides.
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Second Shape (Middle Octagon-like shape):
This shape has straight horizontal/vertical parts and diagonal corners. But since we’re counting *tiles around the edge*, we count each segment where the black line touches a tile edge — even diagonals count as 1 unit per diagonal step? Wait — let’s look carefully.
Actually, in grid-based perimeter problems like this, when a shape has diagonal edges (like cutting off corners), each diagonal still counts as
1 unit for perimeter if it goes from corner to corner of a tile — because you're tracing along the boundary between tiles.
But wait — looking at the middle shape:
- Top horizontal: 6 units
- Right-top diagonal: 1 unit (goes down-right)
- Right vertical: 3 units
- Right-bottom diagonal: 1 unit (goes down-left)
- Bottom horizontal: 6 units
- Left-bottom diagonal: 1 unit (goes up-left)
- Left vertical: 3 units
- Left-top diagonal: 1 unit (goes up-right)
Add them:
6 + 1 + 3 + 1 + 6 + 1 + 3 + 1 =
22
✔ Double-check: You can trace the entire outline and count each segment. Yes, 22.
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Third Shape (Bottom Rectangle):
It’s 8 tiles wide and 2 tiles tall.
Perimeter = 8 + 8 + 2 + 2 =
20
✔ Check: Counting around — yes, 20.
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Final Answer:
Top shape: 20
Middle shape: 22
Bottom shape: 20
Parent Tip: Review the logic above to help your child master the concept of fun perimeter worksheet.
