Square [tex]\( EFGH \)[/tex] is drawn on a coordinate plane. Diagonal [tex]\( FH \)[/tex] is on the line [tex]\( y - 3 = -\frac{1}{3}(x + 9) \)[/tex]. What is the slope of the diagonal [tex]\( GE \)[/tex]?

A. [tex]\(-\frac{1}{3}\)[/tex]

B. [tex]\(\frac{1}{3}\)[/tex]

C. [tex]\(-3\)[/tex]

D. 3



Answer :

To find the slope of diagonal GE in a square, we need to consider the properties of the square's diagonals.

1. Identify the given slope: We are given the equation of the line on which diagonal FH lies:
[tex]\[ y - 3 = -\frac{1}{3}(x + 9) \][/tex]
From this equation, it's clear that the slope of line FH is [tex]\( -\frac{1}{3} \)[/tex].

2. Understand the relationship between the diagonals: In a square, the diagonals are perpendicular to each other. The product of the slopes of two perpendicular lines is always [tex]\(-1\)[/tex].

3. Calculate the slope of GE: If the slope of FH is [tex]\( -\frac{1}{3} \)[/tex], let’s denote the slope of GE as [tex]\(m\)[/tex]. Since FH and GE are perpendicular,
[tex]\[ \left( -\frac{1}{3} \right) \cdot m = -1 \][/tex]
To find [tex]\(m\)[/tex], solve for [tex]\(m\)[/tex] by isolating it on one side of the equation:
[tex]\[ m = \frac{-1}{-\frac{1}{3}} \][/tex]
Simplifying this results in
[tex]\[ m = 3 \][/tex]

Thus, the slope of diagonal GE is [tex]\(\boxed{3}\)[/tex].