maths 7 area and surface

The area of Robin’s rectangular room is 100 square feet. If the width of the room is 5 feet, then what is its length?

A. 25

B. 10

C. 30

D. 20

The area of a rectangular pool is 500 square feet. If the width of the pool is 20 feet, then what is its length?

A.   25

B.   45

C.   50

D.   20

The length of a rectangular duck pond is 18 yards. Its area is 216 square yards. What is its width?

A.   15

B.   24

C.   20

D.   12

Amber just bought a new rectangular desk in her office which is 3 feet wide and 5 feet long. Her office floor is 10 feet by 10 feet in size. Find the total area of space left in the office after the desk is brought in.

A.   15

B.   100

C.   85

D.   115

Jamie needs to cut the grass of his rectangular garden which is 20 yards wide and 34 yards long. There is a square deck that measures 4 yards on one side has no grass portion. What is the total area of grass Jamie will need to cut?

A.   680

B.   16

C.   696

D.   664