Work out the missing area in each pair of similar shapes ( me )

 

Hey its me again. I answered this question of yours and coincidentally I found you again. ^-^

The first shape seems to be scaling up. From 3cm to 12cm. So for this you need to multiply. Using the formula that I gave you last time. 3cm times ___ = 12cm. 4 fits in there, therefore 6cm^2 times 4 = 24cm^2.

The answer for the first one would be 24cm^2. "24" in the blank.

The second shape seems to be scaling down. From 16cm to 8cm. So for this you need to divide. 16cm divided by ___ = 8cm. 2 fits in there, therefore 40cm^2 divided 2 = 20cm^2.

The answer for the second one would be 20cm^2. "20" in the blank.

The third shape seems to be scaling up. From 3cm to 4.5cm. So for this you need to multiply. 3cm times ___ = 4.5cm. Now since we're dealing with decimals, not whole numbers this time you can't really use guess and check as efficiently. So you do the opposite operation, which in this case the opposite of multiplication is division. You take 3cm (the original shape's number) and divide it into 4.5cm. So 4.5cm divided by 3cm = 1.5. 1.5 fits in there, therefore 20cm^2 times 1.5 = 30cm^2.

The answer for the third one would be 30cm^2. "30" in the blank.