Question

Could someone please take a look at This Mathematics problem; I am certain how to explain the work, Thank you.

Answer 1

The slope of a line is found as follows:
$Slope=\frac{rise}{run}$
In triangle ABC the slope of the hypotenuse is 1/3.
In triangle DFA the slope of the hypotenuse is 2/6 = 1/3.
The slopes of the two hypotenuses are equal, therefore the slope of k must be constant between points C and D.