Write two different expressions giving the perimeter of the donkey’s pen

Let's name the sides of the donkey's pen as "length" and "width".

Expression 1: 2(length + width)
This expression calculates the perimeter by adding the length and width together, then multiplying the sum by 2.

Expression 2: length + length + width + width
This expression calculates the perimeter by adding each side of the pen individually. It adds two lengths (both sides of length) and two widths (both sides of width) together.