# I Scaling a set in the plane

#### Mr Davis 97

This is a pretty simple question, I am just trying to clear up confusion. Let $D$ be the rectangle in the plane with vertices $(-1,0),(-1,1),(1,1),(1,0)$. Let $\lambda >0$. Then what exactly does the set $\lambda D$ look like? Is it correct to say that, for example, $2D$ is the rectangle with vertices $(-2,0),(-2,2),(2,2),(2,0)$?

#### Mark44

Mentor
This is a pretty simple question, I am just trying to clear up confusion. Let $D$ be the rectangle in the plane with vertices $(-1,0),(-1,1),(1,1),(1,0)$. Let $\lambda >0$. Then what exactly does the set $\lambda D$ look like? Is it correct to say that, for example, $2D$ is the rectangle with vertices $(-2,0),(-2,2),(2,2),(2,0)$?
Your interpretation seems reasonable to me, although I've never run into any other situations where a set was multiplied by a number.

#### Math_QED

Homework Helper
Your interpretation seems reasonable to me, although I've never run into any other situations where a set was multiplied by a number.
The concept of cosets in group theory is the first thing that comes to mind.

"Scaling a set in the plane"

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