There are 2 shapes on a 8x8 grid. Which shape is closest to the red 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: red right_triangle at (7, 1)
Distance from target shape to brown square at (4, 2): 4
Closest shape is the brown square at (4, 2) with distance 4</think>

<answer>(4, 2)</answer>