Could someone with answering the questions in the images below, i'd really appreciate any given!

6. Both angles are 120 degrees.

Because it is symmetric we know that all of the points are the same.  With the 30 degrees given we can draw a line to make 2 right triangles.  We know that there are 180 degrees in a triangle so when we have a 30 degree side and a 90 degree side the other side muse be 60.

Since we have two right triangles we have 2 60 degree sides next to each other so it's 120 degrees for Y.  The reason Z is 120 degrees is because you have a circle with 2 parts at 120 degrees which is 240.  Since there are 360 degrees in a circle Z must also be 120 degrees.

7. I will do one of each for you, you can do the rest
 First Box
Area= Side * Side or: (x+3)*X= A simplifies to X^2+3X= Area
Perimeter = 2*L + 2*W or  2(X+3) + 2x = P simplifies to 2x + 6 + 2x =P which simplifies to 4x + 6 = P

First Triangle
Area = H*B/2 (Height * Base/2) or x*(x+4)/2 simplifies to X^2+4x/2 =A
Perimeter = S+S+S or:  X + X+4 +2X which simplifies to 4X+4=P 

2. Parallelogram Area = B*H
So we have 4 * ?= 10
Divide both sites by 4 and ?= 2.5cm

If there are four friends then each would get, 1.25 or 1 1/4. so this is how i solved 5 ÷ 4 = 1.25 . hope this ; )