The line y = mx + c has a slope of m.
Parallel line:
A parallel line will also have a slope of m, and should be of the form
y = mx + k
Because the line passes through the point (a,b), therefore
ma + k = b
k = b - ma
The equation of a parallel line is
y = mx + b - ma
   = m(x-a) + b
Perpendicular line:
A perpendicular line will have a slope of -1/m, because the product of slopes should be -1.
The equation for a perpendicular line is of the form
y = -(1/m)x + k
Because the line passes through (a,b), therefore
-(1/m)a + k = b
k = b + a/m
The equation for a perpendicular line is
y = -(x/m) + b + a/m 
   = -(1/m)(x-a) + b
Answer:
Parallel line: 

Perpendicular line: 
 
        
             
        
        
        
<span>According the information given we understand that the room is a regular rectangle, We know that volume = lenght * widht * height, so we start by calculate the room area as length by width, that is 16.4 * 4.5 = 73.8 square metres. Then with 3.26 metres of height, the total volum will 73.8 * 3.26 = 240.58 cubic metres.</span>
        
             
        
        
        
Answer: I think it's a
Step-by-step explanation:
 
        
             
        
        
        
One way to do this is use the fact that the exterior angles of all polygons add up to 360 degrees
So an exterior angle of a regular octagon  = 360 / 8 = 45 degrees.
So each interior angle = 180 - 45 = 135 degrees
so total measure of all angles in octagon = 8 * 135 =  1080 degrees