Point M with coordinates (3, 4) is the midpoint of the line AB and A has the point (-1, 6). What is the point of B? (G2B)

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)

Can someone me out here number 4 plz

We just started the introduction into circles and i have no idea how to do this.