Please answer this math question

The area of a rectangle is 15+5y square feet. which of the following expressions could be the length of the sides of the rectangle, in feet a. 5 and 3y b. 5 and 3+y c. 5 and 5+y d. 3 and 5+3y

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

What is the radical expression that is equivalent to the expression 27 1 over 5?