Idea 10of 15Builds onTurn about a point
Turn it, corner by corner
When a shape turns, where does each corner go?
Today you'll discover
- how to follow one corner round
- where it lands after 90° and 180°
- how to check a drawing
Think firstA right triangle; its square corner is marked
The square corner is at the top right. After a quarter turn clockwise, where is it?
Decide first, then press Next. Keep your eye on the small orange square.
Four small grids. The first holds a right triangle with its square corner at the top right marked by a small orange square, and its turn point, a dot, in the middle. The others show it turned 90 degrees clockwise (the marked corner at the bottom right), 180 degrees (bottom left) and 90 degrees counter-clockwise (top left). The last step shows a house shape.
See the whole ideathe big idea and the key word, in one place
The big idea
In a turn, every corner swings the same way about the point of rotation, which stays still.
Tracing paperTrace the shape, hold the turn point down with a pencil, and turn the paper a quarter or a half turn.
Easy to get wrongDraw a turned shape with a ruler, corner to corner. Place one named corner first, then the rest.
Key word
- point of rotation
- the fixed point a shape turns about; it does not move
Ready to use it?
- Turn a right triangle or a house shape 90° or 180°.
- Say where a named corner ends up.