Lines and Symmetry — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Which pair of objects best represents parallel lines?
A) Clock hands at 3:00
B) Railroad tracks
C) The letter T
D) A pair of scissors
Railroad tracks run side by side at a constant distance and never meet — a perfect real-world example of parallel lines.
2. A stop sign is a regular octagon. How many lines of symmetry does it have?
A) 4
B) 6
C) 8
D) 10
A regular octagon has 8 sides → 8 lines of symmetry.
3. The capital letter T has how many lines of symmetry?
A) 0
B) 1
C) 2
D) 4
The capital letter T has one vertical line of symmetry through its center. It has no horizontal symmetry.
4. Streets that cross to form right angles are examples of what type of lines?
A) Parallel
B) Perpendicular
C) Diagonal
D) Curved
When streets cross at 90° angles, they are perpendicular to each other.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A butterfly has 1 line(s) of symmetry down its body.
A butterfly's body forms a vertical line of symmetry — the left and right wings are mirror images of each other.
2. The two horizontal lines in the letter E are parallel to each other.
The horizontal strokes of the letter E run in the same direction and never converge — they are parallel.
3. A plus sign (+) has 2 lines of symmetry.
A plus sign has 2 lines of symmetry. You can fold it along a vertical line down the middle and along a horizontal line across the middle, and both halves match exactly.
4. A ladder has two long rails that are parallel. The rungs are perpendicular to them.
The two long sides of a ladder are parallel (same distance apart, never meeting), and each rung forms a perpendicular angle with them.
5. The capital letter O has 2 lines of symmetry.
The printed capital letter O typically has 2 lines of symmetry: vertical and horizontal.