33. Two gardens in the shape of regular triangles are bordered in decorative tile. What is the total length of the tile?
\[
3 m \quad 4.5
\]

Step 1 ：Given that the gardens are in the shape of regular triangles, the lengths of the sides of the two triangular gardens are 3m and 4.5m respectively.

Step 2 ：The perimeter of a regular triangle (equilateral triangle) is simply three times the length of one side.

Step 3 ：Calculate the perimeter of the first triangle: \(3 \times 3 = 9\) meters

Step 4 ：Calculate the perimeter of the second triangle: \(3 \times 4.5 = 13.5\) meters

Step 5 ：Add the perimeters of the two triangles to get the total length of the tile needed: \(9 + 13.5 = 22.5\) meters

Step 6 ：Final Answer: The total length of the tile needed is \(\boxed{22.5}\) meters