There are 3 shapes on a 10x10 grid. Which shape is closest to the red trapezoid 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 trapezoid at (3, 8)
Distance from target shape to yellow right_triangle at (9, 1): 13
Distance from target shape to gray square at (6, 3): 8
Closest shape is the gray square at (6, 3) with distance 8</think>

<answer>(6, 3)</answer>