Max needs to paint a wall surrounding a door. The dimer
shown below.
Founding a door. The dimensions on his blueprint are
pue 21
25 ft
5 ft
20 ft
20 ft
12 ft
12 ft
10 ft
10 ft
Which expression can he use to find the area of the wall? Select all that apply.
A (20 x 25) - (5 X 12)
B 10 X 12 + 10 X 12 + 8 X 25
Ć 10 x 20 + 10 x 20 + 5 X 8
D (20 X 15) + (20 x 10)

answer:

328 sq. ft. of walls that need to be painted.

Step-by-step explanation:

Measure the total distance (perimeter) around the room. (10 ft. + 15 ft.) x 2 = 50 ft.

Multiply the perimeter by the ceiling height to get the total wall area: 50 ft. x 8 ft. = 400 sq. ft.

Doors are usually 21 square feet (there are two in this example): 21 sq. ft. x 2 = 42 sq. ft.

Windows average 15 square feet (there are two in this example): 15 sq. ft. x 2 = 30 sq. ft.

Take the total wall area and subtract the area for the doors and windows to get the wall surface to be painted: 400 sq. ft. (wall area) – 42 sq. ft. (doors) – 30 sq. ft. (windows) = 328 sq. ft. of walls that need to be painted.

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4