Finding Perimeter Lengths

Suppose we had to answer this question? 

Where would we start?  Well I would draw a rectangle to start with. I know the rules of a rectangle tell me there will be two sides of equal measure. 

Now I can randomly plug in some pairs of numbers I know will add up to 14m. 

Last step is to complete my diagram and then double check to make sure my sides all add up to 14m. After all, the perimeter is the outside lengths of the shape all added up together!

Problem Solving With Perimeter.

Here's our challenge?  Where to begin???  I'm going to draw a picture to start with. 

And I also know this...

So I have to get to 3000m while running around this block. Each block is going to be 800m if I add up the totals to get the perimeter. So how many laps to get to 3000?