How do you think a beginner could make this ?

Hello . i hope iam not miss posting this in the wrong section . i am preparing to start my first project that would be a chicken coop . i am wondering what is the simplest mehod to make a cut like the one in the picture . the piece of wood would be 2meeter/10cm by 10 cm and the cut would be 5/10 cm . I am planing to buy a circular saw ( smting like this ) . do you think i could do this cut better with a router ( like http://ift.tt/1HyYyeg ?



Any help would be greatelly apreciated :)



thanks .