# How do I find the vertical reaction forces?

The horizontal Force $$A_x$$ is easy but how did they get the vertical forces $$A_y$$ & $$B_y$$? I tried using similar triangles for the Force and length of the sides, somehow I can't manage to solve it. I wonder where I am making a mistake.

• Nice diagram. Anyway, have you tried balancing the forces and moments (about any point)? Aug 20 '19 at 21:03

There are multiple ways to solve this problem but I use the moment equilibrium around the points A and B.

$$A_y 3l-q_0 4l^2=0$$

You can find the $$A_y$$ reaction force from the equation above and use it again in the moment equilibrium around A this time:

$$-4q_0l^2-B_y 3l=0$$

You can also skip the second part, and use your intuition, since the structure is in equilibrium, the vertical forces should cancel each other out, otherwise the structure accelerates.