Robert and his dad want to build a sandbox for his sister's birthday.They wanted it to be 4 feet wide and have an area of 28 square feet.

What is the length of the sandbox?
7?

Robert's dad decided to make the sandbox bigger by extending the length and width of the sandbox by 24 inches. What is the area of the bigger sandbox?

When Robert and his dad finished building the sandbox,it was 2 feet tall.He wanted to fill up the sandbox with new sand.Each bag of sand cost $12 and covers 3 cubic feet. HOw much money will Robert's dad save by only fillinh the sandbox half way?

I don't know how to answer the 2nd and last question

For second question, 24 inches = 2 feet.

(7+2)(4+2) = ?

Third question. 2 feet high divided in half = 1
Take area from above to find cubic feet. Since the change is 1 foot in height, it will be the same value. Divide by 3 and multiply that quotient by 12.

To find the length of the sandbox, we can use the formula for the area of a rectangle: area = length * width. In this case, the width is given as 4 feet and the area is given as 28 square feet. So we can plug in these values and solve for the length.

28 = length * 4
length = 28 / 4
length = 7 feet

So, the length of the sandbox is 7 feet.

Now let's move on to the second question:

If Robert's dad extended the length and width of the sandbox by 24 inches, we need to convert the inches to feet in order to calculate the new area.

Since there are 12 inches in a foot, 24 inches is equal to 24 / 12 = 2 feet. Therefore, the new length and width of the sandbox will be increased by 2 feet.

The new width will be 4 + 2 = 6 feet.
The new length will be 7 + 2 = 9 feet.

To find the area of the bigger sandbox, we use the same formula: area = length * width.

Area = 6 * 9
Area = 54 square feet

So, the area of the bigger sandbox is 54 square feet.

Moving on to the last question:

The sandbox is 2 feet tall. To calculate its volume (capacity), we use the formula: volume = length * width * height.

Volume = 7 * 4 * 2
Volume = 56 cubic feet

If Robert's dad fills the sandbox halfway, he will only need half the amount of sand. So he will need:

(1/2) * 56 = 28 cubic feet of sand.

Since each bag of sand covers 3 cubic feet, we can calculate the number of bags needed:

Number of bags = 28 / 3
Number of bags = 9.33

Since we cannot buy a fraction of a bag, Robert's dad will need to buy 10 bags of sand.

Each bag costs $12, so the total cost would be:

Total cost = Number of bags * Cost per bag
Total cost = 10 * $12
Total cost = $120

By only filling the sandbox halfway, Robert's dad will save the cost of filling the other half of the sandbox, which is $120.