There are 5 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 (4, 3)
Distance from target shape to cyan square at (1, 3): 3
Distance from target shape to orange trapezoid at (0, 4): 5
Distance from target shape to gray right_triangle at (7, 5): 5
Distance from target shape to pink square at (5, 4): 2
Closest shape is the pink square at (5, 4) with distance 2</think>

<answer>(5, 4)</answer>