Substended angle, diameter question

[jehan4141]

We are on lesson 1 and 2, which are vectors and kinematics only. We haven't covered anything else, yet the professor assigned us this problem. Can anybody help me? I have searched google and have yet to understand this problem. Thank you!

To an observer on earth, the moon, which is 3.8x10^5 km away, substends an angle of 0.52 degrees. What is the moons diameter?

Homework Equations

I found on google that S=R x theta

The Attempt at a Solution

The answer is 3500 km, but no matter what configuration I put these values into the equation, I still don't get the right answer.

 

[Spinnor]

I think you have to convert the angle in degrees to an angle in radians for the formula to work? Try that.

 

[jehan4141]

thank you! yes that works!

 

[Ouabache]

alternatively (keeping theta in degrees),
recall from trigonometry, how to determine the length of a http://www.csgnetwork.com/trigtriformulatables.html".