Answer:
53
Step-by-step explanation:
It is either an alternate angle or an opposite angle of the 53 shown.
We know that angles on a straight line add up to 180, so:
53+x=180
x=180-53
x=127
We know that the indicated angle plus x would give 180, so:
?+x=180
?+127=180
?=180-127
?=53
