Trigonometry Subtended angle

[veronica1999]

Deniz notices that the Sun can barely be covered by closing one eye and holding an
aspirin tablet, whose diameter is 7 mm, at arm’s length, which means 80 cm from Deniz’s
eye. Find the apparent size of the Sun, which is the size of the angle subtended by the Sun.


Could I get some hints pls?

Thanks

 

[CaptainBlack]

Deniz notices that the Sun can barely be covered by closing one eye and holding an
aspirin tablet, whose diameter is 7 mm, at arm’s length, which means 80 cm from Deniz’s
eye. Find the apparent size of the Sun, which is the size of the angle subtended by the Sun.


Could I get some hints pls?

Thanks

The angular size of the asprin at arms length is \(7/800\) radian, which is equal to the angular size of the sun.

Converting to degrees this is \((7/800)\times(180/\pi)\approx 0.501^{\circ}\), which agrees with what everyone should know: that the sun and moon have an angular diameter of about a half degree.

CB