Since the picture frame is square, we know that every side is equal length. If one side is 345mm, then every side is 345mm.
Since we are building a picture frame, we want the perimeter of the frame.
perimeter = 345mm + 345mm + 345mm + 345mm = 1380
We need 1380 millimeters which is equivalent to 1.38 meters.
We can multiply the number of meters by the cost of meters to find the total cost:
1.38 * $7 = $9.66
The wood will cost $9.66
