*ignore selected answer haha* just need help answering

Me answer number 3plz explain how you do it

And employees salary increase by $4500 which represents a 15% raise what is the employees new salary

You will get 25 points an image of a rectangular prism is shown below: part a: a cross section of the prism is cut with a plane parallel to the base. what is the name of the shape created by the cross section? explain your answer. (5 points) part b: if a cross section of the prism is cut perpendicular to the base, what would be the shape of the resulting cross section? explain your answer. (5 points)