Moment of forces F and P about points A, B, C, D

[bergausstein]

I just don't know where did the numbers 5,4, and 3 came from. please explain.

I'am asked to do this

assuming clockwise moments as positive, compute the moment of force F = 200 kg and force P = 165 kg about points A, B, C, and D.

the solution picture is here

 

[I like Serena]

I just don't know where did the numbers 5,4, and 3 came from. please explain.

I'am asked to do this

assuming clockwise moments as positive, compute the moment of force F = 200 kg and force P = 165 kg about points A, B, C, and D.

the solution picture is here

That particular force is represented by a vector that goes 4 grid squares to the right and 3 grid squares up.
The triangle identifies its slope.
The hypotenuse of that triangle is 5.