Mary is standing at the edge of a slow-moving river which is one mile wide and she wishes to return to her campground site on the opposite side of the river. She can swim at a rate of 2 mph and walk at a rate of 3 mph. She must first swim across the river to any point on the opposite bank. From there she can walk to the campground, which is one mile down river from the point directly across the river from where she start her swim. What route will take the least amount of time?

What I started to do was find the missing leg of the triangle which is √2 because i figured that would be the quickest route across, but I dont know what to do after that any ideas? Thanks.