Math 2 8 5 Polygons on the Coordinate Plane 2 nd of 3 videos

now before we can find the perimeter we need to add up and find out how long each side is so let me see that one is seven this one is three two three this one is four one two three this one is four this one is four this one is three this one is seven and let's see what's that one that one's ten so guys count on your sides and see how many sides this enclosure has count again no i'm asking you how many sides this enclosure has it does have eight sides let me show you one two three four five 6 7 8. so how many numbers do we need to add together we need to add all eight numbers don't care where you start i'm going to write them down and put little check mark next to each one so make sure that use them all up and don't want to accidentally write numbers down more than should so i'm going to write down that 10 write down that 7 write down that 3 down four three times here's another three and here's another seven so i'm gonna count make sure i've written down all eight numbers one two three four five six seven eight all right let's see what we have 10 20 38 39 42 let's see and this is don't know if this is feet or yards but it's 42 something and think that's what you just said in the college is it 48. 10 20 30 38 it's 42. maybe you wrote you probably just hit number wrong in your calculator now look at this next question find the area now that's an odd shape isn't it let me show you what you can do to make it into shapes that you're more comfortable with you ready leave your numbers there you're going to need them if draw an imaginary line right here you see where i'm drawing it haven't just made one parallelogram and another parallelogram yeah and you know how to find the area of the parallelogram so you just find the area of each parallelogram and put them together okay that's no big deal so big rectangle parallelogram small rectangle or parallelogram i'm going to find the area of each one and this is the simplest formula you just multiply base and height together so let's look at the big one everybody looking at the big one brock was the base length of that big parallelogram brock you're working on the wrong problem honey we're still with the animal enclosure so what's the base length of that parallelogram seven and mia what's the height of this big parallelogram you know what brock your answer is not wrong if you had it turned sideways you're still going to use ten and seven 7. right so for the big one it's going to be 7 times 10 which is 70. now let's focus right here on this small parallelogram looks like rhinoceros is about to walk into it kylie what's the base length of this small parallelogram it is four and brock what's the height of that small parallelogram it is 4 and 4 times 4 is 16. so if put the 70 square units together with the 16 square units that gives me total area of 86. so even though we started off with an odd shape was able to divide it up into shapes that we could work with all right so number four at the bottom are y'all able to read those numbers yeah okay let me know if you cannot read those numbers and you know you're really just counting spaces want you to find the perimeter of this park enclosure and then find the area it's very very similar to number three that we just did you work on that one independently all right so let's take look at this so i'm going to start here in the corner as move to the right that bottom edge is 16 units long when count up this way that's nine now from this corner over to this right here one two three four five that's five from here up to that dot that's three from here over here is seven one two three four five six seven five is from this dot to that dot from this dot down here that's three again from this dot over here let's see what that is one two three four that's four i'm gonna put them right over here yes yes can do that yes ma'am and let's see what is this one two three four five six seven eight nine okay so yeah so mia well the five goes this way and the three goes that way up and then we have seven it's going left to right we've got number another three that's going up and down and then we've got four that's going left and right don't know babe but we do have eight sides and now i've got eight numbers so 16 is right there 9 is right there 5 3 7 3 again 4 and then nine so let's see what we get 25 30 40 47 okay think maybe you hit wrong number is that what you got okay and now we're finding the area well once again we've got an odd shape we can't find the area of that shape but if connect this dot over here to this dot then can make two small one small and one big parallelogram and can find those areas so i'm going to do the big parallelogram and the small parallelogram and once again we have formulas that are easy to use base times height so let's focus on that great big parallelogram kylie what's the base length of that great big parallelogram right here it is 16. brock what's the height of my big parallelogram it is nine everybody excuse me i'm sorry think you're right 144. all right so mia looking just at the small parallelogram what's that base length you're right one is three and the other is seven those are the two numbers you use that's an area of 21 and when put these two areas together get grand total of 165 square units all right good on that one so see we're not doing anything new but mean it is sort of new but this is still good review of the area formulas that you're going to do tomorrow all right so number five find the perimeter and area of the polygon with these vertices want you to do that one want you to do it all by yourself this one is more simple