To find the measure of angle ∠QRS, we first need to know that supplementary angles add up to 180 degrees. Given:
- m∠QRS = (x + 40)°
- m∠SRT = x°
We can set up the equation:
\[ (x + 40) + x = 180 \]
Now, simplify the equation:
\[ 2x + 40 = 180 \]
Next, subtract 40 from both sides:
\[ 2x = 140 \]
Now, divide both sides by 2:
\[ x = 70 \]
Now we can find m∠QRS:
\[ m∠QRS = x + 40 = 70 + 40 = 110° \]
Thus, the measure of ∠QRS is:
\[ \boxed{110°} \]