Hi, I'm having a bit of trouble getting this one problem started:

I have tried using the pythagorean theorem as well as similar triangles but it doesn't seem to be working out. Any help would be appreciated.Painters are painting the second floor exterior wall of a building that adjoins a busy sidewalk. A corridor 2 m wide and 3 m high is built to protect pedestrians. What is the length of the shortest ladder that will reach from the ground over the corridor to the wall of the building?