Anyone know how to answer this questions please help me.
in the diagram below, O is circumscribed about quadrilateral DEFG. What is the value of x?

http://assets.openstudy.com/updates/attachments/53c9b8f0e4b081ba9637cf55-shayday345-1405729589107-66febcfca8ae410fb80effdbddbc2de4.gif

Question

Anyone know how to answer  this questions please help me. 
in the diagram below, O is circumscribed about quadrilateral DEFG. What is the value of x? 
 
http://assets.openstudy.com/updates/attachments/53c9b8f0e4b081ba9637cf55-shayday345-1405729589107-66febcfca8ae410fb80effdbddbc2de4.gif

xapproachesinfinity · Answer

opposite sides of inscribed quadrilateral are supplementary 
meaning they sum up to 180

xapproachesinfinity · Answer

so $$120+(x-10)=180 ~~ \text{solve for x }$$