What is the fast way to model roof trusses

[Daniel_He]

Hi Everyone, now I'm learning to model roof trusses. I have created roof trusses for area 1 as shown in the below picture. In area 2, the size of trusses is getting smaller gradually, I have no idea what's the fast way to multicopy trusses. Could anyone help me, thanks

[Mahmoud Qenawi]

Thank you so much.