There are 3 shapes on a 10x10 grid. Which shape is closest to the brown 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: brown right_triangle at (8, 4)
Distance from target shape to yellow right_triangle at (7, 9): 6
Distance from target shape to blue trapezoid at (3, 3): 6
Closest shape is the yellow right_triangle at (7, 9) with distance 6</think>

<answer>(7, 9)</answer>