What symmetry means
A shape has line symmetry when both sides match across a mirror line.
Symmetry Tool
Draw or inspect shapes against a mirror line to explore line symmetry.
Test a mirror line
Start by watching the orange shape and the pink reflection. When they sit exactly on top of each other, you have found a line of symmetry.
Current check
You found a line of symmetry for the square.
The pink reflected outline sits on top of the orange shape, so both halves match.
Mirror line at x = 160
Try this next
x = 160
Tip: focus on the corners. If the reflected corners miss the original corners, the mirror line is not in the right place yet.
Quick reference
Mini lesson
Move shapes and a mirror line to test whether a figure has line symmetry.
Testing shapes
Squares have more symmetry lines than irregular polygons.
Explore further
Try these next
#1
Vertical symmetry
Place the mirror line in the middle of the shape.
#2
No symmetry
Try an uneven shape and see why the halves do not match.
#3
Multiple lines
Test a square with vertical, horizontal, and diagonal lines.
Keep going