In a standard 2 × 3 grid structure overlaid with 2 adjacent single squares on the side forming a standard textbook square counting puzzle, how many squares are there in total if the count sums up to 13?

How many triangles are present in a figure where a main triangle is divided by two straight lines drawn from its top vertex to the base, and intersected by three horizontal lines parallel to the base?

How many total triangles are there in a standard 4-level triangular grid (a large triangle divided into 16 unit triangles)?