The moon subtends an angle of about 0.532 degrees....

[SaraKiesel]

I need help with this problem. It is probably easier than I think it is but I cant even figure out where to start. Any help would be much appreciated.

The moon as viewed from the Earth subtends an angle of about 0.532 degrees. If the moons diameter is 2160 mi., find the distance from the Earth to the moon.

 

[SaraKiesel]

Nevermind, i figured it out. thanks anyway though.

 

[jwpaine]

Not going to share? Possibly for other students?

 

[SaraKiesel]

If you draw a picture, the process is a little easier to understand. The picture should look like an ice cream cone laying on its side. :lol:

You have to find the long side of the triangle, so you use the formula S = R(angle in radians).

First you change the "0.532 degrees" into radians by multiplying by pi/180. That gives you your angle. You also have S = 2160, which is the diameter of the moon. When you plug them into your formula, you get:

. . .2160 / (0.517 (pi/180)) = r

When you plug that into your calculator, you should get the correct answer.

Hope that helps!