CPM Homework Help : CC2 Problem 8-11

Write an equation to represent this problem and find the unknown side lengths. Use the 5-D Process to help you organize your thinking and to define your variables, if you need to do so. Remember to define your variable.

A trapezoid has a perimeter of $117$ cm. The two shortest sides have the same length. The third side is $12$ cm longer than one short side. The final side is $9$ cm less than three times one short side. How long is each side of the trapezoid?

Help:

Perimeter is the sum of the lengths of all the sides.

More Help:

Create an expression comparing each side with the shortest side, represented by $x$ .

Hint:

Two Shortest Sides: $x$
Third Side: $12+x$
Fourth Side: $3x-9$
Perimeter: $117$ cm

Partial Answer:

Shortest Sides: $19$ cm
What are the other side lengths?
Be sure to know how to get this length and the other lengths.