On a test selena answered 26 out of 30 question correctly .what portion of her answer was correct

Part/Whole=Percent/100
Part=26
Whole=30
Percent= Variable because that is what you want to find out
So now it is 26/30=X/100
You then cross multiply and you get
2600=30X
Divide by 30 and your answer is 86.66667. She got 86.66667% of her questions right. I am not sure if you need to round that or not.
Another way you can do it is Divide 26÷30=.866667 and then multiply by 100 to get 86.66667.

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