About 0.3 degrees, by estimation.
The sixty-to-one rule is useful here. At a distance of 60 units, the angle in degrees and the distance (in units) are about equal for small angles.
Thirty to two inches is the same as sixty to four inches, about a third of a foot, so the angle must be about a third of a degree. Rounded it gives 0.3.
My horribly antiquated TI-82 thinks the answer is about 0.3183 by this methodtan−1(1/180)≈0.3183
