A rectangular floor is 21 feet long and 12 feet wide what is the area of the floor in square yards ?

1 yard = 3 feet
1 square yard = 9 square feet

Method 1 :
Area of the floor
= (21 feet) × (12 feet)
= 252 square feet
= 252/ 9 square yards
= 28 square yards

Method 2 :
Area of the floor
= (21 feet) × (12 feet)
= (21/3 yard) × (12/3 yard)
= (7 yard) × (4 yard)
= 28 square yards

Either convert to yards and multiply to get the area, or multiply to get the area and convert to square yards. Your choice.

http://www.wolframalpha.com/input/?i=21+feet+by+12+feet+in+square+yards

21' x 12' = 7yd x 4 yd = 28 sq yd.

7*4 = 28 yd^2

7 yds x 4 yds = 28 sq yds

Easier to convert those sides feet to yards, then figure the area.

21 feet = 7 yards
12 feet = 4 yards
Area of a rectangle = length times width
7 x 4 = 28
28 square yards.

The area of the floor is 28 square yards.