1989 AMC 8 Problem 11
Attempt Problem 11 of the 1989 AMC 8 below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 1989 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
11.
Which of the five "T-like shapes" would be symmetric to the one shown with respect to the dashed line?
Answer: B
Solution:
Two figures are symmetric with respect to the dashed line when folding the paper along that line makes one coincide with the other. Reflecting across the vertical dashed line swaps left and right while leaving top and bottom unchanged.
Under this reflection the small square in the top-left corner moves to the top-right corner, the straight crossbar changes its slant from "/" to "\", and the stem that points down and to the right must instead point down and to the left. Only one choice has all three of these features.
Thus, the correct answer is B .
Problem 11 in Other Years
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