How to Rotate Any Shape!

okay to rotate you're going to need your protractor your ruler number two pencil let's go so to rotate this shape 90° clockwise around the origin which is the 0 you're going to take your protractor you're going to line it up on the origin okay line up the 0° on the first point you want to rotate so say you want to rotate point a you're going to line up your protractor like this you're going to line up that line right on a and the tricky part is making sure that it lines up nice something like that okay so you're doing a 90° rotation so you're going to go from 0 to 90° uh make a little Mark there at 90 and then you're going to grab your ruler but you could also use your protractor for this next part and just draw a straight line from the point of rotation to that tick mark you made just draw it really lightly okay you are almost done um you're going to notice that point a is two diagonal units away from the origin it's now going to be two diagonal units away from the origin on this line that you just drew so point a is actually going to rotate and it's going to be right here so you can go ahead and label that a prime let's now do point B so again you're going to grab your trusty protractor you're going to line up 0° on B and make sure that the Crosshair of your of your protractor is on the origin something like that okay bling bling now from 0 to 90 like this again you can draw a straight line from the origin to that point so B is going to fall somewhere along this line this one's a little trickier because you can't see how many diagonal units away it is from the origin so this is where your ruler is going to come in handy so what you're going to want to do is you're going to want to measure from B to the origin and figure out how many millimet or cenm it is so it looks like I got about 2.8 or 2.9 CM from the origin I'm going to take my ruler I'm going to start at the origin again but I'm going to go along this line I'm going to measure about 2.8 or 2.9 CM so here's 2.8 right here so that means that point B after it rotates 90° is actually going to land right there okay usually once you have two of the three points you can probably guess where C is going to go so I can kind of see that I'm going to guess that c goes right here I can double check with my protractor so once again I can line up my protractor this time I'm interested in point C so I'm going to line up 0° there I'm going to mark from from 0 to 90 so there's 90° I'm going to draw my line like this and I already see no pun intended I can already see that it's going through the point that I'm guessing um I can confirm with my ruler I can measure it looks like it's about 3.2 CM away so again I'm going to go on that line and I can see that we got about 3.2 CM away so I'm really sure that that is C Prime so once you have that you can grab your ruler and you have successfully rotated your triangle 90° about the origin right on woo good job yeah okay guys say you want to rotate the same shape as last time time except this time we're going to do 180° about the origin this time we're going to rotate again ABC but we're going to go 180° clockwise around the origin um we have a rotation from last time so you actually have two options you could do a 90° rotation on this shape um and that would be equivalent to 180 because 90 + 90 is 180 or um you can do what I'm about to do and I'm going to take my original shape and I'm going to just do the 180 rotation so same idea as before um I'm going to take my protractor and let's say I want to know where point a is going to end up so I line up the Crosshair on the point I'm rotating around so in this case it's the origin I'm going to line up 0° on point a and that just takes a little bit of juggling here so that looks probably about right okay so I'm going to go from 0° I'm going to go all the way to 180 and I'm going to make a little Mark Mark there I'm going to grab my protractor and I'm going to draw a very faint straight line from the origin to that point so now I know that point a is going to land somewhere on that line how far away well it's actually quite easy uh it's two diagonal units away on this side so it's going to be two diagonal units away on this line you can see that it's probably meant to go through that corner so that's going to be a prime um let's say I want to know what happens to point B now so again I'm going to line up my protractor um on 0 0 I'm going to line up 0° on point B uh this is the part where probably taking that extra few uh seconds to make sure that it lines up nicely is going to make a big difference um if you're even off by a few degrees you might get a little bit of a wonky looking picture but if it's on grid paper usually you can see um what's supposed to happen so again I'm going to go from 0° over to 180 make a little tick mark going to grab my protractor I'm going to draw a straight line from the origin through that Mark and I can see that point B is going to land somewhere along this line hopefully um to figure out exactly where along that line is going to land I'm probably going to have to measure from point B to the origin over here so I think we did this last time looks like about 2.8 or 2.9 somewhere in between cenm so again it's going to be that distance on this line and I think I actually kind of messed up the line here um so let's see what happens so yeah it looks like it should land right at about 2.8 which is right here so I'm going to make a DOT you can see that my line is actually a little bit off when I drew the straight line I didn't quite go through that point and I didn't quite go through the origin so this just kind of demonstrates if you kind of mess up just a little bit um what can happen but I know that A and B should be along the same vertical line so that's how I know it needs to land there uh so again to do Point C I'm going to guess that it's probably looks like it should go right through this point here but I'm going to double check with my protractor so again I go on the origin with the crosshairs I line up Point C at 0° like that going to go 0 to 180 make a little tick mark I'm going to this time I'm going to make sure I really go through my origin and I'm going to line up my protractor with that tick mark going to make a really really faint line and you can see that I probably guessed right to be really sure I can grab my ruler measure how far away C is from the origin over here looks like it's about 3.3 CM away it's going to be the same distance along this line so let's see if that works I got 3.3 so I'm pretty sure this is C Prime you're done get your ruler draw your triangle and enjoy your great success perfect

Channel: Matteo Di Muro

Views: 97,429

Keywords: Rotations, Geometry, Graphing, Mathematics, Di Muro

Id: 6pZm55EDSb4

Length: 8min 29sec (509 seconds)

Published: Mon Feb 22 2016