Answer:
x = 35
Step-by-step explanation:
The sum of the angles round a point = 360°
Sum the 4 angles and equate to 360
2x + x + 90 + a = 360 ← substitute a = 165
3x + 90 + 165 = 360, that is
3x + 255 = 360 ( subtract 255 from both sides )
3x = 105 ( divide both sides by 3 )
x = 35
