There are 3 shapes on a 8x8 grid. Which shape is closest to the yellow 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: yellow square at (5, 7)
Distance from target shape to blue trapezoid at (1, 7): 4
Distance from target shape to red right_triangle at (3, 2): 7
Closest shape is the blue trapezoid at (1, 7) with distance 4</think>

<answer>(1, 7)</answer>