There are MANY ways to do this problem, most of them involving breaking it into 3 or four shapes. But this one is easier if you do most of it by taking out the squares and half squares.
The large puppy weighs 20.97 Pounds. This is because 2/3 of a hundred is 66. You would do 4.5 Times 4.66. This equals 20.97. It can be rounded to 21. Hope this helps!
