Answer:
45 degrees
Step-by-step explanation:
∠1 and ∠4 are on a straight line. Therefore, they are supplementary and add to 180 degrees.
∠1+∠4=180
We know that the m∠1 is 135 degrees. We can substitute 135 in for ∠1.
135+∠4=180
Now we have to solve for ∠4. To do this, we need to get ∠4 by itself. 135 is being added on to ∠4. To undo this, subtract 135 from both sides, because subtraction is the opposite of addition.
135-135+∠4=180-135
∠4=180-135
∠4=45
The measure of ∠4 is 45 degrees.
