Answer:
48.
Explanation:
To find the missing number write out the equation : 
67 + 65 + ? = 180.
67 + 65 = 132 
To find out how much more we need you can minus 132 from 180.
180 - 132 = 48. 
Plug it in to see if it works. 
67 + 65 + 48 does equal 180. 
Hope this helps,
Davinia.