Difference between revisions of "2019 AMC 12B Problems/Problem 3"
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==Solution== | ==Solution== | ||
− | We can simply graph the points, or use coordinate geometry, to realize that both <math>A'</math> and <math>B'</math> are, respectively, obtained by rotating <math>A</math> and <math>B</math> by <math>180^{\circ}</math> about the origin. Hence the rotation by <math>180^{\circ}</math> about the origin maps the line segment <math>\overline{AB}</math> to the line segment <math>\overline{A'B'}</math>, so the answer is <math>\boxed{ | + | We can simply graph the points, or use coordinate geometry, to realize that both <math>A'</math> and <math>B'</math> are, respectively, obtained by rotating <math>A</math> and <math>B</math> by <math>180^{\circ}</math> about the origin. Hence the rotation by <math>180^{\circ}</math> about the origin maps the line segment <math>\overline{AB}</math> to the line segment <math>\overline{A'B'}</math>, so the answer is <math>\boxed{\textbf{(E)}}</math>. |
==See Also== | ==See Also== | ||
{{AMC12 box|year=2019|ab=B|num-b=2|num-a=4}} | {{AMC12 box|year=2019|ab=B|num-b=2|num-a=4}} | ||
{{MAA Notice}} | {{MAA Notice}} |
Revision as of 18:59, 18 February 2019
Problem
Which of the following rigid transformations (isometries) maps the line segment onto the line segment so that the image of is and the image of is ?
reflection in the -axis
counterclockwise rotation around the origin by
translation by units to the right and units down
reflection in the -axis
clockwise rotation about the origin by
Solution
We can simply graph the points, or use coordinate geometry, to realize that both and are, respectively, obtained by rotating and by about the origin. Hence the rotation by about the origin maps the line segment to the line segment , so the answer is .
See Also
2019 AMC 12B (Problems • Answer Key • Resources) | |
Preceded by Problem 2 |
Followed by Problem 4 |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | |
All AMC 12 Problems and Solutions |
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