standard_description: Derive using similarity the fact that the length of the arc intercepted by an angle is proportional to the radius, and define the radian measure of the angle as the constant of proportionality; derive the formula for the area of a sector.
problem_activity: Task
Milong and her friends are at the beach looking out onto the ocean on a clear day and they wonder how far away the horizon is.
About how far can Milong see out on the ocean?
If
Milong climbs up onto a lifeguard tower, how far is the horizon in Milong's view?
Mount Shishaldin lies on a narrow peninsula in Alaska  and is pictured here:
[IMG]
If Milong were to stand atop Mount Shishaldin and look out over the ocean, how far would the horizon be?
Based on the answers to the questions above,
is the distance of Milong's visual  horizon proportional to her elevation above the surface of the earth?  Explain.


aligns: no