There are 6 shapes on a 7x7 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 (5, 5)
Distance from target shape to purple trapezoid at (0, 2): 8
Distance from target shape to yellow square at (0, 4): 6
Distance from target shape to gray trapezoid at (0, 3): 7
Distance from target shape to cyan rectangle at (6, 4): 2
Distance from target shape to blue square at (2, 1): 7
Closest shape is the cyan rectangle at (6, 4) with distance 2</think>

<answer>(6, 4)</answer>