Can someone give the answer and explain how to solve this?

the point is that SB is the same length and BU... see?  even thou, the box is a parallelogram... so  1/2SU= BU or 21 :)   maybe by intution it seems like one side might be longer than the other but. b/c both sides have to move.. the line stays the same on each side.. so the crossing point. is half way... always.. :o

Step-by-step explanation:

hello from mrbilldoesmath!

answer:   x^2 + y^2 = 1024

discussion:

the equation of a circle with center (h,k) and radius "r" is

(x-h)^2 + (y-k)^2 = r^2.

in our case

(x-0)^2 + (y-0) ^2 = 32^2 = 1024

you,

mrb