There are 6 shapes on a 10x10 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 (6, 1)
Distance from target shape to red trapezoid at (7, 6): 6
Distance from target shape to gray right_triangle at (7, 3): 3
Distance from target shape to blue rectangle at (9, 8): 10
Distance from target shape to brown square at (8, 7): 8
Distance from target shape to orange rectangle at (8, 1): 2
Closest shape is the orange rectangle at (8, 1) with distance 2</think>

<answer>(8, 1)</answer>