Answer:
(a) 
Step-by-step explanation:
The question is incomplete. (See comment for complete question).
From the completed question, we have:

--- number of pyramids
Required
An expression for the area of the base
The total base length of the pyramid represents the perimeter of the base.
And since the base is a square, then the following relationship exist.

Where L represents the length of each side.
This gives

Make L the subject

The area of the base is then calculated as:


Answer:
m is equals to 49 degree + 31 degree so which means it's 80°
Well,you have the answer on your paper already...
Im pretty sure it is the first one