There are 4 shapes on a 10x10 grid. Which shape is closest to the cyan 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: cyan right_triangle at (1, 3)
Distance from target shape to blue trapezoid at (5, 7): 8
Distance from target shape to yellow trapezoid at (5, 8): 9
Distance from target shape to red square at (5, 6): 7
Closest shape is the red square at (5, 6) with distance 7</think>

<answer>(5, 6)</answer>