A uniform ladder of mass, m, and length, l, leans at an angle, theta, against a rough wall and is on a rough floor. Determine a formula for the minimum angle at which the ladder will not slip if a man reach the top of the ladder.

You posted the same question yesterday, and Steve pointed out to you that you are missing some important data

http://www.jiskha.com/display.cgi?id=1435116033

and yet you posted it again exactly the same way.