123 grams is rounded to nearest whole. write down the minimum possible mass it could have been.

Since we want the minimum value we are going to be rounding up from a smaller number. So we know the whole number will be 122. Now we find the smallest number that will round up which is .5. Answer is 122.5

122.4 would've rounded down.

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's