Answer:

Step-by-step explanation:
Let the unknown angle be x
As the interior angles in a triangle are added up to 180°

Hope this helps you.
Let me know if you have any other questions:-)
see the figure below to better understand the problem
we have that

<h2>The answer is 357.0 feet</h2>
Hello :
<span>the parabola's equation is : f(x) = a(x+3)²-1
</span><span>the coefficient of the squared expression in the parabola's equation is : a
but ; f(4) = 0
0 = a(4+3)²-1
49a-1=0.....a=1/49
f(x) = 1/49(x-3)²-2</span>