How do you find an expression for the perimeter of a shape?

Answer 1

depending on what your shape is labled as, you add all the expressions up around the outside edge. and sides that are the same have the same expression. so, if it is a square or rectange, the sides opposite each other are the same. after putting all of these expressions together, you can then simplify the expression to give you your final answer.

eg.

a rectangle with sides 'x+2' and 'x'.

you know that the oposite sides of the rectangle are the same so now you have all the sides so:

x + x + x+ 2 + x + 2 (simplify)

4x + 4

this is your final perimeter for your rectangle as an expression =P

(other shapes with more than 4 sides can still be done as long as you can find lengths that are the sema side and then add them all together still)