Idea 4of 15Builds onSlide every corner
Flip across the line
Where does a shape land when it flips across a line?
Today you'll discover
- how to count to the line
- where each new corner goes
- what changes in a flipped shape
Think firstA triangle and a mirror line
The corner nearest the line is 2 squares from it. Where does it land after the flip?
Decide first, then press Next. Count squares straight across to the line, never on a slant.
Squared paper with a thick vertical line down the middle and a triangle to its left with corners 8, 6 and 2 squares from the line. Dashed counts run from each corner to the line, then the same counts carry on past it to three new corners, which join into a green triangle facing the other way. The last step shows a horizontal line with a triangle sitting on it.
See the whole ideathe big idea and the key word, in one place
The big idea
A reflection puts each corner the same distance from the line, on the other side.
Easy to get wrongA flip faces the other way. If your new shape points the same way as the start, you slid it instead of flipping it.
For exampleCount straight across, square by square: a corner 2 squares above a side-to-side line lands 2 squares below it.
Key words
- reflection
- a flip: every point goes straight across a line to the same distance on the other side
- line of reflection
- the line the shape is flipped across; it acts like a mirror
Ready to use it?
- Flip a shape across a vertical or horizontal line.
- Check each new corner is the same distance from the line.