In the figure two regular pentagons are shown. Calculate "x". For reference:
In the figure two regular pentagons are shown. Calculate "x".

My progress..I marked the angles I found but I couldn't find the equation to solve
$a_i = \frac{180(5-2)}{5}=108^o\\ \triangle BCG (isosceles) \therefore \measuredangle CGB = 36^o$
If we find $\measuredangle DCF$ the problem is solved because $\measuredangle DJF$ is half of $\measuredangle DCF$


Yes, you got the right answer because $$\measuredangle DCE=360^{\circ}-3\cdot108^{\circ}=36^{\circ},$$ which gives $$\measuredangle CDG=18^{\circ}.$$
