There are 6 shapes on a 8x8 grid. Which shape is closest to the yellow right_triangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: yellow right_triangle at (3, 5)
Distance from target shape to blue trapezoid at (2, 0): 6
Distance from target shape to pink square at (4, 6): 2
Distance from target shape to cyan square at (5, 3): 4
Distance from target shape to gray rectangle at (5, 1): 6
Distance from target shape to red square at (7, 2): 7
Closest shape is the pink square at (4, 6) with distance 2</think>

<answer>(4, 6)</answer>