we know that
If two lines are perpendicular, then the product o their slopes is equal to minus one
so

Step 1
<u>Find the slope of the given line</u>
we have

-------> 
This line is parallel to the y-axis
so
the perpendicular will be parallel to the x-axis
Step 2
The equation of the line perpendicular to the given line is the y-coordinate of the given point
Point 
the equation is

therefore
<u>the answer is</u>

see the attached figure to better understand the problem
Answer:
h = 19.7 ft.
Step-by-step explanation:
Use the Pythagoras Theorem

Now we take square root on both sides,

so the value of h equals 19.7 ft.
Okay well, if you make a graph, Point A (7,0) and Point B (4,6) are in the top right quadrant. and Point C (1,1) and Point D (5,3) are in the top left, top right, and bottom left quadrant (I'll link a photo of the graph.)
so the lines intersect and make it perpendicular
2(m-n^2)-6(n^2+3m)
=2m-2n^2-6n^2+18m
=20m-8n^2
Done ✅ Hope it helps