1) In order to have 2 parrelelograms to be simillar is by haveing them the same shape and The same scale factor and same angles.

2) A way to find missing side lengths are to first divide the shown side lengths like 3 divided by 4 is 0.75 the you multiply 0.75 by the original side lenth and then you have your answer.



3) I found the missing side length by divideing 3 and 7.5 and got 0.4 then multiplied 4 and 0.4 and got 10.