Look at this before-and-after picture: the same shape facing left, then facing right, like it is looking in a mirror. What stayed the same about the shape, and what changed? Have a think before any hands go up.

The interactive flips each shape over a line, one at a time. Watch which way the shape ends up facing, and count how far each corner sits from the line on both sides.

Watch as we build a simple shape on one side of the mirror line and its reflection appears on the other side. Check together that each reflected corner is the same number of squares from the line, and that the shape now faces the other way.

Today we work through these reflections together: flip a triangle across a line that goes up and down, then an arrow the same way, then an L-shape across a line that goes side to side, and finally a shape that sits two squares away from the line. For that last one, count it out loud: two squares this side, two squares that side, so the reflection lands four squares across the line from the start.

What we learned today

• A reflection flips a whole shape over a line so it faces the other way.
• The shape stays exactly the same size.
• Each corner of the reflection is the same number of squares from the line as its matching corner.