There are 4 shapes on a 5x5 grid. Which shape is closest to the red 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: red right_triangle at (4, 3)
Distance from target shape to blue trapezoid at (1, 4): 4
Distance from target shape to purple right_triangle at (1, 0): 6
Distance from target shape to yellow square at (3, 4): 2
Closest shape is the yellow square at (3, 4) with distance 2</think>

<answer>(3, 4)</answer>