In kilometers, the approximate distance to the earth's horizon from a point h meters above the surface can be determined by evaluating the expression

We are given the height h of a person from surface of sea level to be 350 m and we are to find the the distance to horizon d. Using the value in above expression we get:
Therefore, the approximate distance to the horizon for the person will be 64.81 km
Answer:
The standard parabola
y² = -18 x +27
Length of Latus rectum = 4 a = 18
Step-by-step explanation:
<u><em>Explanation:-</em></u>
Given focus : (-3 ,0) ,directrix : x=6
Let P(x₁ , y₁) be the point on parabola
PM perpendicular to the the directrix L
SP² = PM²
(x₁ +3)²+(y₁-0)² = 
x₁²+6 x₁ +9 + y₁² = x₁²-12 x₁ +36
y₁² = -18 x₁ +36 -9
y₁² = -18 x₁ +27
The standard parabola
y² = -18 x +27
Length of Latus rectum = 4 a = 4 (18/4) = 18
They are circle and triangle.
Best of luck in geometry