By definition, the perimeter of a rectangle is given by:
 

 Where, 
 w: width of the rectangle 
 l: length of the rectangle 
 To find the width and length, we use the formula of distance between points: 
 

 For the width we have: 
 

 For the long we have: 
 

 Then, replacing values we have: 
 

 Answer: 
 the perimeter of rectangle EFGH is: 
 
