Square Pegs in Round Holes

1) What is the length of one side of a square peg that can be inserted into the hole as shown?

2) What is the diameter of a hole that would exactly fit the square peg as shown?

3) What diameter hole would exactly fit the rectangular peg shown?

4) What is the width of a square peg with rounded corners that would exactly fit inside the hole as shown?

5) What is the length of the rectangle’s longer side that would exactly fit into the hole as shown?

What is the diameter of a hole that would exactly fit the rounded rectangle as shown?