There are 5 shapes on a 7x7 grid. Which shape is closest to the purple 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: purple right_triangle at (5, 4)
Distance from target shape to cyan square at (2, 3): 4
Distance from target shape to orange right_triangle at (4, 1): 4
Distance from target shape to pink square at (4, 4): 1
Distance from target shape to yellow trapezoid at (5, 1): 3
Closest shape is the pink square at (4, 4) with distance 1</think>

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