Rectilinear shape area and perimeter question help please

[Jignesh77]

Good afternoon,

My son is in year 6 and we're practicing area and perimeter. This is not a homework question. Could someone please explain the answer in detail so I can explain it to him how to solve this type of questions. I really appreciate your help. Thank you in advance.

Mr Jones has 50 m of fencing.
He wants to make a rectilinear enclosure using all the fencing.

a) Draw an example of a shape he could make. Give units on
your diagram.
b) What is the greatest possible area of the enclosure?
c) What is the smallest possible area of the enclosure?

 

[Dr.Peterson]

Good afternoon,

My son is in year 6 and we're practicing area and perimeter. This is not a homework question. Could someone please explain the answer in detail so I can explain it to him how to solve this type of questions. I really appreciate your help. Thank you in advance.

Mr Jones has 50 m of fencing.
He wants to make a rectilinear enclosure using all the fencing.

a) Draw an example of a shape he could make. Give units on
your diagram.
b) What is the greatest possible area of the enclosure?
c) What is the smallest possible area of the enclosure?

First, "rectilinear" means "made of straight lines". He should choose a fairly simple example, such as a square or a triangle. Let him make a picture and label the sides with their lengths, and show it to us so we can discuss it.

Second, finding maximum and minimum is technically far beyond his age, so I have to assume he has either been told some general rule (such as that regular polygons have a bigger area that any other polygon of the same shape, or he is expected to use his intuition to think about it, perhaps trying some examples to discover a rule. (For this, a rectangle will be much easier than a triangle!) Ask what ideas he has about that.

Then we'll have more to talk about. Note that this is not the sort of problem we can just give you "the" answer to.

 

[Jignesh77]

Thank you. I'll follow your advice.