need a clearer explanation for solving this and get the answer which is x=5

4. A ladder is placed with its foot 5.0m from a wall. The ladder touches the top of a 4.0m fence that is 2.0m from the wall. How high up the wall does the ladder reach? (Hint: use similar triangles and show all of your work) (5) 3.0m 2.0m 5.0m X 3 5 3 ( 8 ) = Jwa - 235