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## Homework Statement

An observer on the earth observes the angle subtended by the diameter of the moon to be 0.009199 radians. If the moon is 234,800 miles away, what is its diameter?

## Homework Equations

Egrav= -Gm1m2/r

57 rad=1 deg

## The Attempt at a Solution

Alright this one is really bugging me. What is the diameter of the moon? The answer, 3476km. But is the question asking something else, taking into account the distance of the moon from earth? Surely this shouldn't matter. What importance does the angle have in the problem?

I've played around with the numbers, and combinations of equations. I don't think the equation for gravitational energy applies, but perhaps there is a way to integrate it.

Thanks.