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

<answer>(6, 5)</answer>