There are 4 shapes on a 7x7 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 (1, 2)
Distance from target shape to gray right_triangle at (5, 3): 5
Distance from target shape to orange square at (1, 3): 1
Distance from target shape to blue trapezoid at (3, 2): 2
Closest shape is the orange square at (1, 3) with distance 1</think>

<answer>(1, 3)</answer>