November 2009
Beginner
368 pages
8h 55m
English
Content preview from Head First 2D Geometry
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
54 Chapter 2
what does “the same” mean?
The design tells us that some triangles are repeated
The designer made a note saying that the two mountain
triangles are the same but rescaled, or different sizes.
There’s also a note saying that the mountain tip is the same
triangle as the whole mountain.
But what exactly does he mean by “the same triangle”?
Jim: Yeah, I mean, the designer is talking nonsense. One of
them is bigger than the other. How on earth can they be the
same?
Frank: Well, maybe he was talking about angles. Can you have
two triangles with the same angles but with different lengths?
These notes are a big hint
about the missing information.
Same triangle?
I don’t get what
this means.
120
56
6060
37.5
30
40
48
40
6
60
41º 53º
This corner also
90
Hand draw the
sun and rays
Frank
Jim
Mountain
tip triangle
is the same
shape
triangle as
the whole
mountain
The two mountain triangles
are the same shape, but
rescaled/flipped
you are here 4 55
similarity and congruence
GEOMETRY Construction
Can you have two triangles with the same angles but with different lengths?
1) Cut or tear three narrow strips of paper, making them slightly different lengths.
2) Make them into a triangle and draw around it on some scrap paper.
3) Now fold each of your strips of paper in half, join them up to make a triangle again, ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.