There are 6 shapes on a 4x4 grid. Which shape is closest to the green 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: green right_triangle at (1, 2)
Distance from target shape to purple trapezoid at (2, 1): 2
Distance from target shape to orange right_triangle at (1, 1): 1
Distance from target shape to brown rectangle at (2, 2): 1
Distance from target shape to yellow rectangle at (1, 3): 1
Distance from target shape to pink right_triangle at (3, 0): 4
Closest shape is the orange right_triangle at (1, 1) with distance 1</think>

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