It's difficult to make out what the force and displacement vectors are supposed to be, so I'll generalize.
Let <em>θ</em> be the angle between the force vector <em>F</em> and the displacement vector <em>r</em>. The work <em>W</em> done by <em>F</em> in the direction of <em>r</em> is
<em>W</em> = <em>F</em> • <em>r</em> cos(<em>θ</em>)
The cosine of the angle between the vectors can be obtained from the dot product identity,
<em>a</em> • <em>b</em> = ||<em>a</em>|| ||<em>b</em>|| cos(<em>θ</em>) ==> cos(<em>θ</em>) = (<em>a</em> • <em>b</em>) / (||<em>a</em>|| ||<em>b</em>||)
so that
<em>W</em> = (<em>F</em> • <em>r</em>)² / (||<em>F</em>|| ||<em>r</em>||)
For instance, if <em>F</em> = 3<em>i</em> + <em>j</em> + <em>k</em> and <em>r</em> = 7<em>i</em> - 7<em>j</em> - <em>k</em> (which is my closest guess to the given vectors' components), then the work done by <em>F</em> along <em>r</em> is
<em>W</em> = ((3<em>i</em> + <em>j</em> + <em>k</em>) • (7<em>i</em> - 7<em>j</em> - <em>k</em>))² / (√(3² + 1² + 1²) √(7² + (-7)² + (-1)²))
==> <em>W</em> ≈ 5.12 J
(assuming <em>F</em> and <em>r</em> are measured in Newtons (N) and meters (m), respectively).
624 is how much is deducted from his pay every month
For a better understanding of the solution provided here, please find the diagram attached.
In the diagram, ABCD is the room.
AC is the diagonal whose length is 18.79 inches.
The length of wall AB is 17 inches.
From the given information, we have to determine the length of the BC, which is depicted a 
, because for the room to be a square, the length of the wall AB must be equal to the length of the wall BC.
In order to determine the length of the wall BC, or , we will have to employ the Pythagoras' Theorem here. Thus:
Thus, 
inches
and hence, the given room is not a square.
ANSWER: square root of 10
Rule: Pythagorean Theorem (a^2 + b^2 = c^2; side^2 + second side^2 = hypotenuse^2)
(substitute the missing side w/ a variable)
x^2 + 7^2 = (sqrt. 59)^2
x^2 + 49 = 59
x^2 = 10
x = sqrt. 10
Answer:2.73
Step-by-step explanation: 2.73
