Clara is building a triangular garden. She wants the length of the longest side to be three more than twice as long as the length of the shortest side, and the third side will be twelve feet long. What expression could she write to determine the perimeter of the triangle if s represents the length of the shortest side? (Recall that perimeter is the distance around a shape.)

The simplified expression would be 3s + 15. In order to find this we need to write an equation for the longest side. Since it's 3 more than twice as much as the smallest side (s), we can express it as 2s + 3. Now we simply add all 3 together and simplify. 2s + 3 + 12 + s -----> simplify3s + 15