Answer: The length of AB is 2 units.
Step-by-step explanation: We are given that the trapezoid ABCD is an isosceles one, where
AB = 2x, BC = 2x + 2 and AD = 4 units.
We are to find the length of side AB of the trapezoid.
We know that
in an isosceles trapezoid, the lengths of two non parallel sides are equal.
So, in ABCD, we have
\(AD=BC\\\\\Rightarrow 4=2x+2\\\\\Rightarrow 2x=2\\\\\Rightarrow x=1.\)
Therefore, the length of AB will be
\(AB=2x=2\times1=2~\textup{units}.\)
Thus, the length of AB is 2 units.
