Can someone me with part a & part b?

Part A.
Perimeter is the total sum of all the outside lenghths

The shape is a rectangles, so the opposite lengths are the same so we can do the following to get the perimeter of the outer frame:

5 + 7 + 5 + 7 =24in.

Part B.
Area = the height of the shape times the base of the shape.

So for the area inside would be :
4 x 6 = 24in²

And the area outside would be:
5 x 7 = 35in²