Here is a reference to the Inscribed Quadrilateral Conjecture it says that opposite angles of an inscribed quadrilateral are supplemental.
Step-by-step explanation:
The conjecture, #angleA and angleC# allows us to write the following equation:
#angleA + angleC=180^@#
Substitute the equivalent expressions in terms of x:
#x+2+ x-2 = 180^@#
#2x = 180^@#
#x = 90^@#
From this we can compute the measures of all of the angles.
#angleA=92^@#
#angleB=100^@#
#angleC=88^@#
#angleD= 80^@#