Answer:
The correct option is;
21 ft
Step-by-step explanation:
The equation of the parabolic arc is as follows;
y = a(x - h)² + k
Where the height is 25 ft and the span is 40 ft, the coordinates of the vertex (h, k) is then (20, 25)
We therefore have;
y = a(x - 20)² + 25
Whereby the parabola starts from the origin (0, 0), we have;
0 = a(0 - 20)² + 25
0 = 20²a + 25 → 0 = 400·a + 25
∴a = -25/400 = -1/16
The equation of the parabola is therefore;

To find the height 8 ft from the center, where the center is at x = 20 we have 8 ft from center = x = 20 - 8 = 12 or x = 20 + 8 = 28
Therefore, plugging the value of x = 12 or 28 in the equation for the parabola gives;
.
20 multiplied (times) 4 is equal to 80 c:
L=3$-x×2 x=D hope this helps?
Please provide more context for our brains to understand your problem (: thank you!
Answer:
≈ 39.7ft
Step-by-step explanation:
The Pythagorean theorem:

(a and b are the two shorter legs and c is the largest leg, which is also the opposite side of the right angle)
First, the value of a and c is given. So, we can go ahead and plug those value in and then solve for b.


To find b, we have to get it by itself. So we subtract 2025 from both sides then square root both sides. Resulting in:

≈ 39.7ft