There are 3 shapes on a 10x10 grid. Which shape is closest to the red square 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 square at (8, 7)
Distance from target shape to yellow rectangle at (4, 5): 6
Distance from target shape to gray right_triangle at (8, 8): 1
Closest shape is the gray right_triangle at (8, 8) with distance 1</think>

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