How to enable Pattern Screen lock in Samsung Galaxy Grand2(SM-G7102)?

a). Tap on Apps as shown below.

b). Now tap on Settings icon and then tap on Device option as shown below.

c). Tap on Lock screen as shown below.

d). Now tap on Screen lock.

e). Tap on Pattern security as shown below.

f). Now draw the pattern of your choice then tap on Continue and then re-draw the pattern to confirm then tap on Confirm as shown below.

g). Now set backup PIN of your choice that must contain atleast 4 numbers. Tap on Continue and then enter and confirm the same PIN then tap on OK as shown below. 

NOTE : If you forget your pattern, you can enter your backup PIN to unlock.