You need to order carpet for a room that has a length that is three times its width. if the area of the room is 432 square feet, find the width of the room.

Let
x> the length of a room
y> the width of a room

we know that
Area of a room=x*y
Area of a room=432 ft²
so
432=x*y> equation 1

x=3y> equation 2

substitute equation 2 in equation 1
432=[3y]*y>432=3y²
y²=432/3
y²=144> y=√144> y=12 ft
x=3y> x=3*12> x=36 ft

the answer is
the width of the room is 12 ft

Yes, two vertical lines can be complementary