SOLUTION

--Static code

DECLARE
   angle1 NUMBER := 70;    
   angle2 NUMBER := 80; 
   angle3 NUMBER ; 
BEGIN
      angle3 := 180 - (angle1 + angle2);
      DBMS_OUTPUT.PUT_LINE('The third angle of the triangle is ' || angle3 || ' degrees.');
END;
/
    



--Dynamic code 
DECLARE
   angle1 NUMBER := &angle1;    
   angle2 NUMBER := &angle2;
   angle3 NUMBER ; 
BEGIN
      angle3 := 180 - (angle1 + angle2);
      DBMS_OUTPUT.PUT_LINE('The third angle of the triangle is ' || angle3 || ' degrees.');
END;
/