The perimeter is the distance around the outside of a 2D shape. The distance can be measured in units like millimetres, centimetres, metres and kilometres. To work out the perimeter, add up the ...

Archimedes' method finds an approximation of pi by determining the length of the perimeter of a polygon inscribed within ... he determined that pi was less than 3 1/7 but greater than 3 10/71.

So 10, 15, and 20. We know that the outside distance, or the perimeter of that shape would be 20 inches. So now let's look at our plans here. What we have for my drawing, and this is a model.

So you're going to walk all around the outside of the park? The outside edge of a shape is called the perimeter. It's easy to know how far you're going to walk. We just measure the perimeter.