Answer:
13 sides. 
Step-by-step explanation:
 (n - 2) = 1980 / 180 = 11. 
 n = 13
When the sum of the interior angles is 1980 degrees, the convex polygon will have 13 sides. 
i hope this helps and is right! p.s. i really need brainliest :)
 
        
             
        
        
        
The number π is a mathematical constant, the ratio of a circle's circumference to its diameter, commonly approximated as 3.14159. It has been represented by the Greek letter "π" since the mid-18th century, though it is also sometimes spelled out as "pi" (/paɪ/