math help!!?

3 ⤊

To find the area of a composite shape, you can add areas of simpler shapes. why does this not work for the perimeter?

2006-09-20 11:10:03 · 2 answers · asked by - ѕoичтα. ☮ 4 in Education & Reference ➔ Homework Help

2 answers

Because you will end up adding line segments in the middle of the shape that are not part of the perimeter. In adding up all of the sides, you add many sides that are not part of the shape.

It works for area because you are dividing the shape, calculating, and putting the pieces back together.

Hope this helps.

2006-09-20 11:18:38 · answer #1 · answered by sparkly_chrimsa 4 · 2⤊ 0⤋

because you would be counting the common edges twice.

2006-09-20 18:18:19 · answer #2 · answered by banjuja58 4 · 1⤊ 0⤋