Problem number six. Bruno is making this large triangle using identical small triangular tiles. How many more tiles does Bruno need to complete the large triangle? Three, four, five, six, or seven. We can add lines to the bigger white parts to divide them into triangles of the same size as the other tiles. Now we just need to count. One, two, three, four, five, six. So Bruno needs six more tiles. The answer is D, six.

Bruno

triangular tiles

large triangle

counting tiles

answer six