Geometry Preferably Ms. Sue
posted by BaileyBubble .
Lucinda wants to build a square sandbox, but she has no way of measuring angles. Which of the following explains how she can make sure the sandbox is square by measuring only length?
A)Arrange four equallength sides, so the diagonals bisect each other.
B)Arrange four equallength sides, so the diagonals are equal lengths also.
C)Make each diagonal the same length as four equallength sides.
D)Not possible; Lucinda has to be able to measure a right angle.
I thought it was B but then a friend of mine said it was d and I didn't know if he was right or not so now im second guessing myself. am I right or is he?

Its B, sorry for not being Ms. Sue

lol its alright. thanks so much! :) I love it when im right

I believe your friend is right.
Check it out. On a piece of graph paper draw a parallelogram. Do the diagonals bisect each other? 
In order for it to be a square, the diagonals need to be the same length. In a parallelogram (if you are talking about a rhombus), they do bisect, but the diagonals are not equal in length.

http://www.mathsisfun.com/geometry/parallelogram.html
http://www.mathsisfun.com/geometry/rhombus.html 
No disrespect intended, but you disproved your point with those links Ms. Sue. The second link, at the very bottom it asks this question:
Example: A rhombus has diagonals of 6 m and 8 m, what is its Area?
Squares have equal diagonals. 
Thanks, Joey. You're right.
Bailey was right with her answer of b.