Answer:
x + 90 + 63 = 180
Step-by-step explanation:
We do not have the value for angle B so we have to assume that B plus the 45 is 90. using this info we can see that A + 90 + 63 is equal to the line, which is 180(as all lines are). We can then get the equation x + 90 + 63 = 180
