The perimeter of the large square is 24 and the area is 36 units the perimeter of the small squares are 4 and the areas are 1 unit. All together the perimeter is 29 and the area is 38.
The two triangles will be similar (same shape, and each side of one triangle the same multiple of the corresponding side of the other triangle), but not necessarily the same size.
The key word here is "similar;" be sure you understand what that means in trig.