Similar shapes Flashcards
What does enlargement mean?
To make something bigger.
What does reduction mean?
To makes something smaller.
What is a scale factor ?
We usually assign it the letter k . And it tells us how much to times by to get a new shape (either a reduction or an enlargement).
For example, if k=2, this means the image is twice as big as original shape.
What does image when talking about transformations?
It’s the new shape that comes out after the transformation.
You can think of it like a picture. When you take a picture, you get an image. It looks a lot like the real thing you took a picture of, but it’s not exactly the same.
What’s the definition of “similar figures”?
The ratio of corresponding sides is the same for all of the shape’s sides.
How do you use angles to prove two triangles are similar?
Show that two angles are the same.
Which angles of intersecting lines are the same?
The opposite ones.
Which angles on these parallel lines are the same?
The ones inside the “Z” *and opposite angles.
What do we know about angles that are reflected on a mirror (or water surface)?
The angles next to the mirror (or water) are the same.
How do you show these triangles are similar?
- Common angle (the shapes literally use the same angle).
- Z-rule (since the lines are parallel).
How do you show these triangles are similar?
- Opposite angles of intersecting lines.
- Z-rule (since the lines are parallel).
How do you show these triangles are similar, given that the bottom is reflective water?
- Z-rule (since the lines are parallel).
- Angles reflecting off water (or a mirror) are the same.
What is an “angle of elevation”?
It’s the angle between the floor and an upward line.
What is an “angle of depression”?
It’s the angle between the ceiling and a downward line.
