Answer:
34°
Explanation:
I'm a little confused by your question. But I solved the question this way.
y+12+2y-18+2y+16=180
Why 180° you ask? Because the angle sum interior of a triangle always measures 180°.
(y+2y+2y)+(12+−18+16)=180
5y+10=180
Subtract
5y+10−10=180−10
5y=170
divide
5y/5=170/5
y=34