The perimeter of an object is found by adding all of the sides. The sides of his frame would be 2 ft, 2 ft, 1.5 ft (18 inches / 12 inches per foot = 1.5 feet), 1.5 feet. Adding these together we get a total length of 7 feet. However, he may want to use a slightly longer board to account for any errors!
Answer:

Step-by-step explanation:
Given
Points:


Required
Determine the equation of line that is perpendicular to the given points and that pass through 
First, we need to determine the slope, m of FG

Where
--- 
--- 



The question says the line is perpendicular to FG.
Next, we determine the slope (m2) of the perpendicular line using:


The equation of the line is then calculated as:

Where





Multiply through by 2

Add x to both sides


Hence, the line of the equation is 
Answer:
42=7(z-3)
We simplify the equation to the form, which is simple to understand
42=7(z-3)
Reorder the terms in parentheses
42=+(+7z-21)
Remove unnecessary parentheses
+42=+7z-21
We move all terms containing z to the left and all other terms to the right.
-7z=-21-42
We simplify left and right side of the equation.
-7z=-63
We divide both sides of the equation by -07 to get z.
z=9