if 9m away from deep point, m1 also away from 9m to radius line.
so if we draw 2 x 2y to 1 half side of circle, y is connected with 9m, x is connected to 6m.
2 x = 150 sec
if i say 1 x 6m 2x 12m
x =75 sec =12.5 sec
(2x +2y ).2 is whole circle round
12.5*15*2
750 second is answer
is it true?
