Introduction to perimeter

Oh man! I forgot perimeter, Julia can you tell me what is perimeter?
Okay class, let's revise Perimeter.
No problem John I will tell you what Perimeter is. To find perimeter we need to add the length of all the sides from outside of a shape.
Can you give me some real life examples, I do not understand??.
Okay class! time for your recess.
Okay! lets go to the playground and explore.
let's find out the perimeter of this sand box by adding all the sides or if all the sides are equal then multiply one side x 4.
Oh! now I got it.
okay, one side of the box is 5m, it means that this sandbox's perimeter is 5 + 5 + 5 + 5 = 20m or 4 x 5 = 20m
Yes! Bingo! you got it right, now let's go to class before we are late.
Julia! now I can easily calculate this bulletin board's perimeter.
I`m happy to hear this, let`s calculate.
As this is rectangular in shape so it will have different measurements, the formula for this shape will be P= 2(l+b) = 2 ( 30 + 40)= 2 x 70 P= 140 m
Great job! I would like to thank Abha ma`am for explaining perimeter so easily.