Finding theta when moment is max

[goldfish9776]

Homework Statement

to achieve max moment , the 4 kN must br perpendiclar to 20m , right ? so, i formed a cloased triangle and use sine rule to find the
tetha , 25/ sin90 = 4/sin tetha , i gt my tetha = 9.2 degree , but the ans given is 33.6degree
i gt max moment = 80Nm

Homework Equations

The Attempt at a Solution

 

[SteamKing]

Homework Statement

to achieve max moment , the 4 kN must br perpendiclar to 20m , right ? so, i formed a cloased triangle and use sine rule to find the
tetha , 25/ sin90 = 4/sin tetha , i gt my tetha = 9.2 degree , but the ans given is 33.6degree
i gt max moment = 80Nm

Homework Equations

The Attempt at a Solution

You've applied the law of sines incorrectly to this problem. You can't measure the length of one side of a triangle in units of Newtons, and another in units of meters.

 

[DEvens]

And don't forget that the pivot point is shown as 1.5 m above the ground.