What is a block? Describe a block by streets

Question

Cambridge Dictionary gives this definition about "block"

the distance along a street from where one road crosses it to the place where the next road crosses it, or one part of a street like this, especially in a town or city

Consider the area pointed out by the red rectangle shown below

From the left to the right, the first part "the distance along a street" becomes "the distance along Independence Avenue"; then second part "where one road crosses it to the place where ..." becomes

"where 4th st SW crosses it to the place where ..."

question#1: Is the area pointed out by the red rectangle called a block?

question#2: Does "it" here refer to Independence Avenue?

question#3: Does "the place" here refer to the block?

question#4: I guess "one part of a street like this" means some other style/shape of block, What does that refer to?

Answer 1

1) The definition in Cambridge dictionary is not describing a "block" as the area you have outlined in red on your map. It is describing it in terms of the distance along one street. Let us take Independence Avenue as that street. Now, start at the intersection of that avenue with 4th Street. Now, move along Independence Avenue to the right (east), until you arrive at 3rd Street. That is a block, as they are defining it. It is a distance along Independence from 4th to 3rd.
2) Yes, "it" refers to the street.
3) The word "place" just means the intersection.
4) I don't know what they mean by "one part of a street like this".

Note that the definition given is of a linear distance along a street, not of a two-dimensional shape.
However, "block" can also mean the two-dimensional shape, as you can see in the definition from Merriam-Webster dictionary.
M-W "block"
At that link, definition 6a(1) refers to a shape like the square on your map, while 6a(2) : refers to the linear distance along a street.