Explain the following sentence with neat diagram.
A tree far away from us can get hidden behind a book held very close to our eyes.

Explanation

i. Every object placed in front of our eyes subtends an angle with the eye.
ii. The apparent size of the object depends on the angle subtended by that object with our eye.
iii. As shown in the figure, the tree even though large in size being far away (at point P') subtends smaller angle `(beta)` with the eye.

iv. Whereas, if we hold a book very close to eye, i.e., at point P, then the book subtends larger angle `(alpha)` with the eye.
v. As `alpha` is greater than `beta`, the apparent size of the book is bigger than that of tree. In this way, a tree far away from us can get hidden behind a book held very close to our eyes.