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9 ft.Find the surfacearea of thecomposite figureshown.15 ft.[? ] square feet15 ft.15 ft.If you'd like,you can use acalculator.Enter

9 ft.Find the surfacearea of thecomposite figureshown.15 ft.[? ] square feet15 ft-example-1
User ItechDroid
by
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1 Answer

30 votes
30 votes

Let's find the surface area of the composite figure shown.

The top of the figure is a square base pyramid while the bottom is a square prism.

To find the surface area of the composite figure, find the surface area of the square base pyramid and the surface area of the square prism.

To find the surface area of the square pyramid, apply the formula:


SA=a^2+2al

Where:

a = 15 ft

l is the slant height = 9ft

Thus, we have:


\begin{gathered} SA=15^2+2(15)(9) \\ \\ SA=225+270 \\ \\ SA=495ft^2^{} \end{gathered}

The surface area of the square pyramid is 495 square feet.

Now, let's find the area of the square prism.

Apply the formula:


SA=2a^2+4ah

Where:

a = 15 ft

h = 15 ft

We have:


\begin{gathered} SA=2(15)^2+4(15)(15) \\ \\ SA=2(225)+4(225) \\ \\ SA=450+900 \\ \\ SA=1350ft^2 \end{gathered}

The surface area of the square prism is 1350 square feet.

To find the surface area of the composite figure, add the area of the square pyramid and square prism.

We have:

Surface area = 495 square feet + 1350 square feet = 1845 square feet.

Therefore, the surface area of the compposite figure is 1845 square feet.

ANSWER:

1845 sqaure feet.

User Mrebval
by
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