Two angles are supplementary if the sum of their measures is 180 degrees. Given the measures of the angles:
- m∠QRS = (x + 40)°
- m∠SRT = x°
Since the angles are supplementary, we have the equation:
Substituting the expressions for the angles:
Now, combine like terms:
Next, subtract 40 from both sides:
Then, divide by 2:
Now that we have the value of
Thus, the measure of ∠QRS is