There are 5 shapes on a 8x8 grid. Which shape is closest to the red rectangle 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 rectangle at (3, 4)
Distance from target shape to brown square at (1, 5): 3
Distance from target shape to cyan right_triangle at (3, 2): 2
Distance from target shape to yellow right_triangle at (3, 6): 2
Distance from target shape to blue right_triangle at (5, 6): 4
Closest shape is the cyan right_triangle at (3, 2) with distance 2</think>

<answer>(3, 2)</answer>