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an engineer has 60:1 scale drawing of a bridge. the dimensions of the scaled bridge beck are 36 inches by 4 4/5 inches. what is the area of the actual bridge deck in square feet?

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User Twaldron
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1 Answer

2 votes

Answer: To find the area of the actual bridge deck in square feet, we first need to find the dimensions of the actual bridge deck.

Let's assume the actual length of the bridge deck is L feet, and the actual width of the bridge deck is W feet.

The dimensions of the scaled bridge deck are given as 36 inches by 4 4/5 inches. To convert these dimensions to feet, we divide by 12 since there are 12 inches in a foot:

Length of scaled bridge deck = 36 inches / 12 = 3 feet

Width of scaled bridge deck = 4 4/5 inches / 12 = 4.4 feet

Now, we know that the scale is 60:1, which means that 1 unit on the scaled drawing represents 60 units in reality. So, we can set up the following proportion:

Actual Length / Scaled Length = Actual Width / Scaled Width

L / 3 = W / 4.4

Now, let's solve for L in terms of W:

L = (W / 4.4) * 3

Next, we need to find the area (A) of the actual bridge deck, which is given by:

Area (A) = Length (L) * Width (W)

Substitute the value of L from the previous equation into the area formula:

A = ((W / 4.4) * 3) * W

Now, let's express the area in square feet by dividing by 144 (since there are 144 square inches in a square foot):

A = ((W / 4.4) * 3) * W / 144

Finally, we can simplify the expression and find the area in square feet:

A = (3W^2) / (144 * 4.4)

A = (3W^2) / 633.6

Now, we don't have the exact value of W in feet, so we cannot provide the precise area. However, if you have the value of W, you can plug it into the equation above to find the area of the actual bridge deck in square feet.

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