There are 5 shapes on a 6x6 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 (1, 0)
Distance from target shape to gray right_triangle at (0, 1): 2
Distance from target shape to green rectangle at (5, 1): 5
Distance from target shape to orange rectangle at (2, 3): 4
Distance from target shape to purple trapezoid at (4, 1): 4
Closest shape is the gray right_triangle at (0, 1) with distance 2</think>

<answer>(0, 1)</answer>