According to the query of Baidu Library, the method of quickly drawing a planar pentagon on a metal plane is as follows:

1. First, determine the five vertices of the Pentagon. These five vertices can be represented by the numbers 1, 2, 3, 4 and 5 respectively.

2. Starting from the number 1, along the edge of the metal plane, clockwise or counterclockwise, the numbers 1 to 5 are used to indicate the order of vertices respectively.

3. At each vertex, make a right-angle mark. This can be marked at each vertex by tapping, pressing or using other methods with hands or tools.

4. Continue to mark each vertex until five vertices are marked on the metal plane.

5. Finally, a planar pentagon is obtained by connecting these five marks.