Click on the graph until the graph of a line with undefined slope appears.

The graph with the vertical line.

Step-by-step explanation:

All vertical lines have an undefined slope.  Horizontal lines have zero slope, and diagonal lines have a slope.

When calculating a slope for a vertical line, you would have to divide by zero. The quotient of any number and 0 are undefined, as you cannot divide by zero.  This is what makes vertical lines have an undefined slope.

Hope this helps.

the answer i think is a)

step-by-step explanation:

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.