Idea 2of 24Builds onAn angle is a turn
Lay one angle on another
How can you compare two angles that point different ways?
Today you'll discover
- how to compare angles without numbers
- where to put the copy's corner
- how to read which is bigger
Think firstP lies flat; Q is turned
P and Q point different ways. What is a fair way to compare them?
Decide first, then press Next. Watch where the copy's second arm lands.
Angle P lying flat on the left and angle Q turned up and to the right. A dashed copy of P slides across and turns until its corner sits on Q's corner and one arm lies on Q's arm; its other arm reaches past Q's, and the gap between them is shaded. The last step shows P turned to point up and Q tipped a little.
See the whole ideathe big idea and the key word, in one place
The big idea
To compare angles, lay a copy of one on the other: corner on corner, arm on arm.
No tracing paper?Fold a scrap of paper to match one angle, then hold the folded corner in the other angle. The folded paper is your copy.
Easy to get wrongLine up the corners first. A copy that sits away from the vertex gives the wrong answer, even if the arms seem to match.
Key word
- traced copy
- a copy of a shape or angle drawn on see-through paper, so it can be moved and laid on another
Ready to use it?
- Compare two angles by laying a copy of one on the other.