2020 AMC 12A Problems/Problem 6: Difference between revisions
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==Problem 6== | |||
<math>\textbf{(A) } | In the plane figure shown below, <math>3</math> of the unit squares have been shaded. What is the least number of additional unit squares that must be shaded so that the resulting figure has two lines of symmetry? | ||
<asy> | |||
import olympiad; | |||
unitsize(25); | |||
filldraw((1,3)--(1,4)--(2,4)--(2,3)--cycle, gray(0.7)); | |||
filldraw((2,1)--(2,2)--(3,2)--(3,1)--cycle, gray(0.7)); | |||
filldraw((4,0)--(5,0)--(5,1)--(4,1)--cycle, gray(0.7)); | |||
for (int i = 0; i < 5; ++i) { | |||
for (int j = 0; j < 6; ++j) { | |||
pair A = (j,i); | |||
} | |||
} | |||
for (int i = 0; i < 5; ++i) { | |||
for (int j = 0; j < 6; ++j) { | |||
if (j != 5) { | |||
draw((j,i)--(j+1,i)); | |||
} | |||
if (i != 4) { | |||
draw((j,i)--(j,i+1)); | |||
} | |||
} | |||
} | |||
</asy> | |||
<math>\textbf{(A) } 4 \qquad \textbf{(B) } 5 \qquad \textbf{(C) } 6 \qquad \textbf{(D) } 7 \qquad \textbf{(E) } 8</math> | |||
Revision as of 14:49, 1 February 2020
Problem 6
In the plane figure shown below, 
of the unit squares have been shaded. What is the least number of additional unit squares that must be shaded so that the resulting figure has two lines of symmetry?
![[asy] import olympiad; unitsize(25); filldraw((1,3)--(1,4)--(2,4)--(2,3)--cycle, gray(0.7)); filldraw((2,1)--(2,2)--(3,2)--(3,1)--cycle, gray(0.7)); filldraw((4,0)--(5,0)--(5,1)--(4,1)--cycle, gray(0.7)); for (int i = 0; i < 5; ++i) { for (int j = 0; j < 6; ++j) { pair A = (j,i); } } for (int i = 0; i < 5; ++i) { for (int j = 0; j < 6; ++j) { if (j != 5) { draw((j,i)--(j+1,i)); } if (i != 4) { draw((j,i)--(j,i+1)); } } } [/asy]](http://latex.artofproblemsolving.com/0/9/8/098f8098c7103b004757d1977d2bd6d459831eb3.png)
