Question

the A&N painting Co. was hired to paint the inside of a community center building that has 4 units. each unit is an activity room in the shape of a rectangular solid with a length of 30 feet and a width of 20 feet. the ceilings are 9 feet tall. assuming that they do not have to paint the floor or ceiling, how many square feet of wall space is there that needs to be painted?

Answer 1

3,600 square feet

Explanation:

Answer 2

Each room has width a, length b and heigth c. Let's use following formulas for area:
Floor and ceiling:
A1=a*b
Left and right wall:
A2=b*c
Front and back wall:
A3=a*c

a=30ft
b=20ft
c=9ft

We do not need to paint floor and ceiling, so total area that needs to be painted is:
A(unit)=2*A2+2*A3
A(unit)=2*b*c+2*a*c
A(unit)=2*20*9+2*30*9
A(unit)=360+540
A(unit)=900ft^2

We have 4 units so total area that needs to be painted is:
A(total)=4*A(unit)
A(total)=4*900
A(total)=3600ft^2