the phone’s size is important
It’s a problem of scale…
The design Liz picked was originally created in 2007, when
phones were a lot bigger than the one Liz has today. In fact,
the design is twice as big as the space available on the back of
Liz’s phone for etching!
his design needs t
be updated t
…but how big a problem is it?
How come there weren’t any units on the drawing? If
they’d put units we could have seen whether it fit before we
A:You’re right, we could have. In this case, though, the lengths
on the diagram wouldn’t be normal measures like millimeters or
inches, but a special measure used by the etching machine.
But shouldn’t the drawing still have a scale? Wouldn’t
we be best to add one now?
A:For now we can just adjust the lengths we’ve got to work
with—we can safely assume that whatever units the etcher uses,
they aren’t going to change before we etch again. But in the next
chapter we’re going to look at using scales in a lot more detail.
70 Chapter 2