There are 3 shapes on a 7x7 grid. Which shape is closest to the cyan 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: cyan right_triangle at (6, 1)
Distance from target shape to purple right_triangle at (1, 6): 10
Distance from target shape to yellow right_triangle at (4, 3): 4
Closest shape is the yellow right_triangle at (4, 3) with distance 4</think>

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