A Place for Ddol-Ddol to Play
Note to teachers: the lesson you saw in the video was a warm up activity for this lesson. But the warm up activity was so successful, it replaced this lesson on the day of the filming. This activity shares all the math challenges with Table for 22, and is the only worksheet we have. Sincerely, Teaching Channel
You want to help Suney build a rectangular pen for her dog, Ddol-Ddol. You have 40 meters of fencing, each in 1-meter lengths, to build the pen.
1-meter
You must build a pen with the largest area, using all 40 meters of fencing, so that Ddol-Ddol has plenty of room to play. Your fence must:
· Be fully enclosed, no doors or windows.
· Have the same height all around the pen.
· Each piece of fencing must be joined side to side, with no space in between.
· Each piece of fencing must be used WHOLE, no cutting into smaller pieces.
Help Suney by determining all the different possibilities for the pen and then decide which pen provides the largest area for Ddol-Ddol. You might want to build the pens on grid paper first, so that it will be easier to determine the area.
Record your data about each possible plan in a table with these column headings:
LENGTH WIDTH PERIMETER AREA
1) Which design would give Ddol-Ddol the most space for playing.
2) Which design would give Ddol-Ddol the longest running space?
Ddol-Ddol’s Play Pen
LENGTH (m) / WIDTH (m) / PERIMETER (m) / AREA(square meters)
*Perfect Rectangle
A rectangle which can be built up of squares all of different sizes is called perfect.
In November 1958, the cover Scientific American showed this diagram on its cover.
Each of the interior rectangles is a square. If square D is 81 square units and square C is 64 square units, what is the area of the other seven squares?
What is the area of the entire figure?
What is the perimeter of the entire figure?
Explain your solutions.
Perfect Rectangle Extension Activity
List all the dimensions of possible rectangles that have the same perimeter as the perfect rectangle above.
On a separate piece of paper, describe what you notice about your data.
LENGTH (m) / WIDTH (m) / PERIMETER (m) / AREA(square meters)