Mia needs to cut the third board to match the width of the shelter. How many feet of board will she need to cut off the existing board to reach this goal? The third board is 42 inches, the width of the shelter is 3 feet
Since there are 12 inches in a foot, the shelter is 3 feet * 12 inches per foot = <<3*12=36>>36 inches wide.
To match the width of the shelter, Mia needs to cut off 42 inches - 36 inches = <<42-36=6>>6 inches of board.
Since there are 12 inches in a foot, Mia needs to cut off 6 inches / 12 inches per foot = <<6/12=0.5>>0.5 feet of board. Answer: \boxed{0.5}.
Can you shorten your answer?
Mia needs to cut off 0.5 feet of board.
To determine how many feet of board Mia needs to cut off to match the width of the shelter, we first need to convert the measurements to the same unit.
The width of the shelter is given as 3 feet, and the third board is given as 42 inches. Since there are 12 inches in a foot, we can convert the 42 inches into feet by dividing it by 12.
42 inches รท 12 inches/foot = 3.5 feet
So the third board is 3.5 feet wide.
To find out how many feet of board Mia needs to cut off, we subtract the width of the shelter from the width of the third board.
3.5 feet - 3 feet = 0.5 feet
Therefore, Mia needs to cut off 0.5 feet or half a foot from the existing board to match the width of the shelter.