# TrigonometrySubtended angle

#### veronica1999

##### Member
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

##### Well-known member
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