Hello Everyone, I have to solve this quadrilateral problem and no idea where or how to start

top left corner is A

bottom left corner is B

bottom right corner is C

top right corner is D

Find a way to get the values of CD and DA

AB - BC = DA - CD

AB - CD = DA - BC

AB + DA = BC + CD

I'd start by naming the lengths: AB = w, BC = x, CD = y, DA = z. Then the equations are:

w - x = z - y

w - y = z - x

w + z = x + y

This is 3 equations in 4 variables which usually isn't solvable. You can get them to standard form for linear systems:

w - x + y - z = 0

w + x - y - z = 0

w - x - y + z = 0

Solving gives:

w = z

x = z

y = z

But there's no way to find z. Sorry.