Is this correct plz tell me if you know

It is! It looks like what you did here was to take 3/5 of 3 1/4, first by dividing by 5, and then by multiplying by 3. Just remember to leave your units (cups) on at the end! Also, you had a step there where you multiplied the improper fraction 3 1/4 = 13/4 by 5/5, so I’d show that step in your work.

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

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.