四下第四單元
周長與面積 Perimeter and Area 

4-1

My friend perimeter

He’s a bit of an outsider

He’s on edge today

Then again he always seems to be that way 

My friend area

Lives his life within the perimeter

He takes up a lot of space

You can always find him all over the place 

Perimeter is the distance around a shape=adding all of the sides together. 

4-2