Question
A child's desk is made so that the dimensions are two-thirds the dimensions of a full-size adult desk.
Suppose the top of the full-size desk measures 54 inches long by 36 inches wide.
What is the perimeter and area of the topof the child's desk?
Suppose the top of the full-size desk measures 54 inches long by 36 inches wide.
What is the perimeter and area of the topof the child's desk?
Answers
Reiny
Areas of similar figures are proportional to the square of the sides
area of larger top = 54x36 = 1944
area of kid's desk/1944 = (2/3)^2 = 4/9
area of kid's desk = (4/9)(1944)
= 864 inches^2
perimeter of big top = 2(54+36) = 180
perimeter of kid's top = (2/3)(180) = 120 inches
or
dimensions of kids top
= (2/3)(54) by (2/3)(36
= 36 by 24
area of little top = 36(24) = 864
perimter of little top = 2(36+24) = 120
area of larger top = 54x36 = 1944
area of kid's desk/1944 = (2/3)^2 = 4/9
area of kid's desk = (4/9)(1944)
= 864 inches^2
perimeter of big top = 2(54+36) = 180
perimeter of kid's top = (2/3)(180) = 120 inches
or
dimensions of kids top
= (2/3)(54) by (2/3)(36
= 36 by 24
area of little top = 36(24) = 864
perimter of little top = 2(36+24) = 120