Which term describes the point where the perpendicular bisectors of the three sides of a triangle intersect?

Which questions would most a reader identify the author's purpose for writing? check all that apply. what type of text is this? what type of reviews did the book receive? how many copies of the book have been sold? what is the central idea? how does this text make one feel?

Find the distance between the pair of points a(-1,8) and b(-8,4)

What is the distance between the points (2, 5) and (5,9)?