Final answer:
Marsha needs 52.5 feet of wallpaper border to cover the perimeter of her bedroom, which measures 13 3/4 feet by 12 1/2 feet.
Step-by-step explanation:
To calculate the amount of wallpaper border Marsha needs for her bedroom, we first need to determine the perimeter of the room. The perimeter is the total distance around the room, which can be found by adding together the lengths of all four walls. Since Marsha's room is 13 ¾ feet long and 12 ½ feet wide, we calculate the perimeter as follows:
Perimeter = 2 × (Length + Width)
= 2 × (13 ¾ feet + 12 ½ feet)
= 2 × (13.75 feet + 12.5 feet)
= 2 × 26.25 feet
= 52.5 feet
So, Marsha needs 52.5 feet of wallpaper border to go around her entire bedroom.