In the plane figure shown below, 3 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?
Answer Choices
A. 4
B. 5
C. 6
D. 7
E. 8
In the plane figure shown below, 3 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?
Answer Choices
A. 4
B. 5
C. 6
D. 7
E. 8