The answer is 1808.64 ft²

To calculate area of square we need to find radius r. Radius is a half of a diameter:
r = d/2

The blueprint:
d = 18 cm
r = 18/2 = 9 cm

<span>The blueprint has a scale of three centimeters to four feet. Actual radius r1 is:
</span>3 cm : 4 ft = 18 cm : r1
After crossing the products:
r1 = 4 ft * 18 cm : 3 cm
r1 = 24 ft

The area of the circular base of the fountain is:
A = r1² * π
π = 3.14
r1 = 24 ft

A = 24² * 3.14
A = 1808.64 ft²

3 0

3 years ago

If w = 12 units, x = 7 units, and y = 8 units, what is the surface area of the figure? Figure is composed of a right square pyra

bearhunter [10]

Answer:

720 sq units.

Step-by-step explanation:

Length and width of square prism, w = 12 units

Height of square prism, x = 7 units

Height of square pyramid, y = 8 units

Please have a look at the attached image.

Here 2 Surfaces will not be exposed which are base of the square pyramid and the top of the square prism i.e. 2 square surfaces will not be exposed.

Here, surface area of the composite figure will be:

<em>Surface Area of Composite Figure = Lateral surface area of Square Pyramid + Surface Area of 5 surfaces of the square prism</em>

For finding the lateral surface area of pyramid, we need to find the slant height of the pyramid.

Let slant height be $l$ units.

Using pythagoras theorem, we can find out the value of $l$ .

As per theorem:

$Hypotenuse^{2} = Base^{2} + Height^{2}\\$

$\Rightarrow l^{2} = (\dfrac{w}{2})^{2} + y^{2}\\\Rightarrow l^{2} = (\dfrac{12}{2})^{2} + 8^{2}\\\Rightarrow l^{2} = {6}^{2} + 8^{2}\\\Rightarrow l^{2} = 36+64 = 100\\\Rightarrow l = 10\ units$

Lateral surface area of square prism = 4 $\times$ Area of triangular surface

$\Rightarrow 4 \times \dfrac{1}{2}\times Base \times Slant\ Height\\\Rightarrow 4 \times \dfrac{1}{2} \times 10 \times 12\\\Rightarrow 240\ sq\ units$