Find the lengths of the diagonals of this trapezoid. when the given length for the sides are (-b,c), (b,c),(a,0), (a,0)

Answer 1

As drwls pointed out in your previous post below this one, you have a typo

I will assume that you missed a negative sign in your last point and it should have been (-a,0)

So the diagonals run from (-b,c) to (a,0) and
from (b,c) to (-a,0)

I will do one, you do the other,
first diagonal = √(a-(-b))^2 + (0-c)^2 )
= √(a^2 + 2ab + b^2 + c^2)