Art2020

Hi, I just bought the dewalt DHS790AT2 flexvolt miter saw and was going to build a greenhouse for my 1st project. The plans for the greenhouse require a 1.5" deep x 3.5" long cut on 4x4x8 & 10' for the base. I'm new to this so was wondering if it's possible to make this type of shallow sweeping cut like this or if I need to make several cuts up to this length. Is there a trick to this or would I need a jig saw to accomplish this task? Thanks, Art