PLS HELP 100 Points do questions 4 , 5 , and 6 on paper!!!

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?

Eric drove 275 miles in 5 hours. at the same rate how long would it take him to drive 495 miles?

Dawn is selling her mp3 player for 3 4 of the original price. the original price for the mp3 player was $40. how much is she selling her mp3 player for?