There are 4 shapes on a 7x7 grid. Which shape is closest to the gray 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: gray right_triangle at (4, 5)
Distance from target shape to cyan square at (5, 3): 3
Distance from target shape to green square at (2, 0): 7
Distance from target shape to brown rectangle at (2, 1): 6
Closest shape is the cyan square at (5, 3) with distance 3</think>

<answer>(5, 3)</answer>