In an inscribed quadrilateral the sum of the opposite angles equal 180°and the sum of all angles are equal to 360°
mes (A+B+C+D)=360°
mes[(2x-7)+(2x+3)+(x+4)+(D)] =360°
Since D+B =180°, then D= 180° - (2x+3). or (180-20-3), Replace D by its value:
mes[(2x-7)+(2x+3)+(x+4)+(180-2x-3)] =360°, Solve for x
x=61° & B=2x + 3 ==> (2).(61) +3 = 122+3 =125
