An art museum has a pentagon-shaped room. When drawn to scale on a coordinate grid, the corners of the room are points (18,20):
B(4,20): C(4,4): D(16.2): E(22.10), shown in feet. The walls are 10 feet high.
The museum is going to paint four of the walls: AB, BC, DE, and AE. Assume one gallon of paint is enough to cover 400 square feet.
How many gallons of paint should the museum purchase? Enter your answer as a whole number.

Respuesta :

Answer:

[tex]2\ gal[/tex]

Step-by-step explanation:

we know that

the formula to calculate the distance between two points is equal to

[tex]d=\sqrt{(y2-y1)^{2}+(x2-x1)^{2}}[/tex]

we have

[tex]A(18,20),B(4,20),C(4,4),D(16.2),E(22.10)[/tex]

step 1

Find the distance AB

we have

[tex]A(18,20),B(4,20)[/tex]

substitute in the formula

[tex]d=\sqrt{(20-20)^{2}+(4-18)^{2}}[/tex]

[tex]d=\sqrt{(0)^{2}+(-14)^{2}}[/tex]

[tex]AB=14\ ft[/tex]

step 2

Find the distance BC

we have

[tex]B(4,20),C(4,4)[/tex]

substitute in the formula

[tex]d=\sqrt{(4-20)^{2}+(4-4)^{2}}[/tex]

[tex]d=\sqrt{(-16)^{2}+(0)^{2}}[/tex]

[tex]BC=16\ ft[/tex]

step 3

Find the distance DE

we have

[tex]D(16.2),E(22.10)[/tex]

substitute in the formula

[tex]d=\sqrt{(10-2)^{2}+(22-16)^{2}}[/tex]

[tex]d=\sqrt{(8)^{2}+(6)^{2}}[/tex]

[tex]d=\sqrt{100}[/tex]

[tex]DE=10\ ft[/tex]

step 4

Find the distance AE

we have

[tex]A(18,20),E(22.10)[/tex]

substitute in the formula

[tex]d=\sqrt{(10-20)^{2}+(22-18)^{2}}[/tex]

[tex]d=\sqrt{(-10)^{2}+(4)^{2}}[/tex]

[tex]d=\sqrt{116}[/tex]

[tex]AE=10.77\ ft[/tex]

step 5

Find out the area of the four walls

To determine the area sum the length sides and multiply by the height of the walls

so

[tex]A=(AB+BC+DE+AE)h[/tex]

substitute the given values

The height of the walls is 10 ft

[tex]A=(14+16+10+10.77)10[/tex]

[tex]A=(50.77)10[/tex]

[tex]A=507.7\ ft^2[/tex]

step 6

Determine the number of gallons needed to paint the four walls

we know that

one gallon of paint is enough to cover 400 square feet

using proportion

[tex]\frac{1}{400}\ \frac{gal}{ft^2}=\frac{x}{507.7}\ \frac{gal}{ft^2}\\\\x=507.7/400\\\\x= 1.27\ gal[/tex]

Round up

[tex]x=2\ gal[/tex]