The student was asked to create a 1 square meter shape using newspaper and then change the perimeter while keeping the area the same. Their original shape was a square with sides of 1m and an area of 1m2. Their new shape was an icosagon with 20 sides and the same area of 1m2, but a greater perimeter of 1,991cm due to the longer sides of the new shape. The student learned about perimeter, area conservation, and how shapes can have the same area but different perimeters.
1. My Square Meter Investigation
The Task:
I was asked tomake 1square meter using newspaper, scissors and
measuring tapes. Then, I needed to change the perimeter of the
shape, but keep the area the same. This is calledconservation of
area.
It was a fun investigation because it was fun to cut the paper and it
was fun to work with my team. It was challenging for me because it is
hard tomeasure all the sides witha ruler and to be very accurate.
Original Shape:
The dimensions of my shape were 1m x 1m, or
100cm by 100cm. This shape was asquare. It
had an area of 1m2 or 10,000cm2. It had a
perimeter of 400cm or 4m.
New Shape:
My new shape was anicosagon (20 sides).The
area of my new shape was still 1m2 or
10,000cm2. I know this becauseI didn’t
add or cut off the area of the shape. The
perimeter of my new shape isgreater
than the original. It is 1,991cm or
19.91m. I worked this out by adding all
the sides. I think the new perimeter is
greater because my new shape has
many sides and they are long sides so
this makes the perimeter much greater
than four short sides of the square.
Reflection:
During this investigation, I learned what perimeter means and how
to work it out. I learned what a square meter looks like and how it
can be made. It made me think abouthow to make a new shape with
same area and a different perimeter.I learned that shapes can have
the same area but different perimeters. I enjoyedmaking the new
shape and being creative. I still have questions about the area of
shapes where the sides have decimals (like 1.6m). I want to learn
how to multiply with decimals so I can find area of these shapes.