Related Rates: Kite Angle Decreasing at 200 ft of String Out

[dethnode]

Homework Statement

A kite 100 ft above the ground moves horizontally at a speed of 8 ft/s. At what rate is the angle between the string and the horizontal decreasing when 200 ft of string has been let out?

Homework Equations

The Attempt at a Solution

I have done the pythagreon therom and found the horizontal to be 173.2050808

Aside from that i am lost can someone help get me started?

 

[HallsofIvy]

Homework Statement

A kite 100 ft above the ground moves horizontally at a speed of 8 ft/s. At what rate is the angle between the string and the horizontal decreasing when 200 ft of string has been let out?

Homework Equations

The Attempt at a Solution

I have done the pythagreon therom and found the horizontal to be 173.2050808

Aside from that i am lost can someone help get me started?

The Pythagorean theorem doesn't tell you anything about the angle. Since the height is opposite the angle the line makes with the horizontal on the ground, and the length of the string is the hypotenuse, use the definition of sine.