A rectangle measures 3 cm. by 4 cm. If the length of each side doubles, what's the new area?
3 answers
The new area is 24 cm2.
The doubled dimensions are 2 • 3 cm = 6 cm and 2 • 4 cm = 8 cm
New area = 6 cm • 8 cm = 48 cm²
New area = 6 cm • 8 cm = 48 cm²
NO
area of original = 3*4 = 12 cm^2
area of new one = 6*8 = 48 cm^2
or
the areas of similar figures are proportional to the square of their side
old : new = 1^2 : 2^2 = 1 : 4
so 4 times as big
area of original = 3*4 = 12 cm^2
area of new one = 6*8 = 48 cm^2
or
the areas of similar figures are proportional to the square of their side
old : new = 1^2 : 2^2 = 1 : 4
so 4 times as big