The probability (making a number of assumptions) is the ratio of the area of

the cross to that of the square.

The area of the cross is the area of the square minus 4 times the area of one

of the triangles.

hence the required prob is:

(144-4*8)/144=7/9

opps.. area of one triangle is 16 not 8 so prob is:

(144-4*16)/144=5/9

RonL