Answer:
x=15º
Explanation:
A triangle's angles add up to 180º.
∠A=30º
∠C=180º-45º
∠B=xº
To find ∠B we have to first find ∠C.
Since ∠C does not have an angle, knowing that a straight line is 180º we can subtract it from 45º to find ∠C.
180-45=135
∠C=135º
Now add ∠A and ∠C.
30+135=165
Subtract the sum from 180º
180-165=x
x=15º
Hope this helps :)