Stacking and trunking

Hello,

I have a question regarding trunking in combination with stacked switches. In my example I have two switches that are stacked, and an unstacked switch. I've placed all sales employees in VLAN 10 (first switch in stack) and the management employees in VLAN 20 (second switch in stack)  on the stacked switches. The servers are on VLAN 30 on the unstacked switch.

Do I need to assign trunkports between the two stacked switches in order to enable the stacked switches to communicate?

Thanks in advance!