For the installation of a decorative wall paper Tricia will need 70 ft of the border to decorate the wall of her master bedroom.
The measures of the room is 18 ft by 14 ft.
So, the length of the room (l) = 18 ft
The width of the room(w) = 15 t
As we know that, perimeter of rectangle is 2(l×w).
We will get perimeter of he room = 2l × 2w
= 2(18) × 2(14)
= 70 ft.