Why is the verse an example of iambic pentameter

You haven't provided the verse you were given, but I can answer your question anyway.

A pentameter is a type of a verse line that consists of five metrical feet.

One type of metrical feet is called an iamb. One iamb consists of an unaccented (unstressed) syllable followed by an accented (stressed) syllable.

Based on this information, we can conclude that the iambic pentameter is a line that consists of five iambs. It was often used by William Shakespeare. The following verse from Shakespeare's A Midnight Night's Dream is a good example of iambic pentameter:

And I do love thee: therefore, go with me;

I'll give thee fairies to attend on thee,

And they shall fetch thee jewels from the deep,

And sing while thou on pressed flowers dost sleep

1.creeping like a snail is a simile used in this poem and it means the child is going to school unwillingly./a child is unwilling to go to school.

2. man becomes very frail and loses his physical strength when he becomes old, so much that his leggings that used to fit him snugly when he was in his youth are now too loose for him to wear, and that his shank has shrunk so much that this worldly stage is too big for a feeble actor like him. although, 'his youthful hose' just refers to his leggings/pants/ to shrink from danger; to shrink from contact.

3.the words "sans" means "without." it is a french word that is often used in english even today. so he is saying that in the last age of a man, the man is without eyes, taste, or anything else. he also says that this is the "last stage of all" and that it is the stage that ends a man's "history."

hope this !