Answer:
In order to calculate area of a square, 'A' be the area of square and the length of the square be 'a'. Then we need to calculate A= a*a. Step 2 :- Accept as input, the length of the sides of the square, and store the value in variable a. Step 3 :- Calculate the area of the square (a*a) and store in a variable A.
Explanation:
 
        
                    
             
        
        
        
Answer:
B. Change the router's default administrative password.
Explanation:
Whenever a user purchase a router for wireless network, a default password has been set for the device, which can be easily accessible to different users on the internet or that particular network. This will  lead to unsecured that particular user in terms of hacking or stealing data or personnel information easily.
To make sure the security of customer on private network, the technician should change the router default password.  
 
        
             
        
        
        
Answer:
True.
Explanation:
Microsoft Word refers to a word processing software application or program developed by Microsoft Inc. to enable its users to type, format and save text-based documents.
In Computer science, there are specific key combinations (short cut) that avail end users the opportunity to perform specific functions without having to go through a series of step. 
For example, when you press the Alt button and function key 4 (F4) at the same time, it would close the current open window.
Hence, Alt + F4 is a short cut key that can be used to close a document in MS word.