APEF area = trapezoidal area-three triangular areas.

Let time t be 1t, 2t.

Area S EFB=(3/5)*t square

Area S PCE=5t-t square

PDA Southern Region =24-4t

The area of S APEF=54-24+4t-5t+t square -(3/5)*t square, that is =30-t+(2/5)*t square.

The question is whether 5/9 of APEF, that is, 54*5/9=30, becomes that the square of -t+(2/5)*t is equal to zero, and the function of -t+(2/5)*t has a minimum value of -5/8 at 5/4, and is zero at 0 and 5/2, that is, at 0 and 2.5 seconds.