Calculating the perimeter of a rectangle is really easy and an important part of 7th-grade math.

The perimeter is the total distance around the outside of the rectangle. This means adding up all four sides.

To find the perimeter, you only need to know the lengths of the two sides: the length (we'll call it ( l )) and the width (we can call it ( w )). The formula to use is:

[ \text{Perimeter} = 2 \times (l + w) ]

For example, if you have a rectangle that is 5 meters long and 3 meters wide, you first add those two numbers together:

[ 5 + 3 = 8 ]

Then, you multiply by 2:

[ 2 \times 8 = 16 ]

So, the perimeter of this rectangle is 16 meters.

Here are a few tips to remember:

• Always use the same units when measuring length and width.
• It can be helpful to draw the rectangle and label the sides, especially when working on more tricky shapes or word problems.

Once you get the hang of calculating the perimeter of a rectangle, it will be easier to find the perimeter of other shapes too!