Circle O and circle P, with radii 3 and 8, respectively, are both tangent to line l at H. Enter all possible lengths of OP separated by commas.
Sketch it. If O & P are on opposite sides of I, then OP is 8 + 3 = 11
If O & P are on the same side of I, then OP is 8 – 3 = 5
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