How can I concatenate arrays in a loop?

New to Julia
1

I’m trying to create a Array{Float,2} with a for loop

julia> r = [1 0 0;0 0.85 0.5;0 0 1];

julia> coord = [(0, 0, 450),(400, 0, 450),(400, 600, 450),(0, 600, 450)];

julia> t = [r*collect(i) for i in coord]
4-element Array{Array{Float64,1},1}:
 [0.0, 225.0, 450.0]
 [400.0, 225.0, 450.0]
 [400.0, 735.0, 450.0]
 [0.0, 735.0, 450.0]

Desired output:

3×4 Array{Float64,2}:
   0.0  400.0  400.0    0.0
 225.0  225.0  735.0  735.0
 450.0  450.0  450.0  450.0
2 
r*hcat(collect.(coord)...)
# or
[r[j,:]'*collect(i) for j in 1:3 ,i in coord ]