There are 3 shapes on a 7x7 grid. Which shape is closest to the gray 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: gray right_triangle at (4, 5)
Distance from target shape to blue square at (5, 4): 2
Distance from target shape to green trapezoid at (6, 2): 5
Closest shape is the blue square at (5, 4) with distance 2</think>

<answer>(5, 4)</answer>