After 2 or 4 seconds, P is on B, and the branch line DP is a straight line DB, and the area is the same, so I don't explain it.
3. There should be two answers, namely 1:2 and 2: 1.
It is easy to get that when t=4 is 2: 1, that is, when P is at point B, it will not be explained.
To get the result of 1:2, p must be on the AB line. When it is on the AB line, the area of the triangle ADP is easy to calculate, and the length of the bottom is fixed as AD=8, so only the height, that is, the Y coordinate of the P point, is considered. Because the trapezoidal area of 12√3 is fixed, it is only necessary to make the area of triangle ADP equal to one third of the trapezoidal area.
It is easy to get that when the Y coordinate of point D is √3, the ADP area of the triangle is =4√3.
Knowing the Y coordinate and branch AB, it is easy to find out the length of BP.
So t= CB+BP