00:01
So in this problem, what we're going to want to do is we're going to find the lengths of all three sides and then add them together to find the perimeter.
00:09
So we'll start by just looking at all three sides individually.
00:13
We'll start with a, b.
00:15
And a, b, the points are 4 .4, 4a, and b is 1 negative 4.
00:24
So we'll start with these two order pairs.
00:27
We'll say this is my point 1 and this is my point 2.
00:30
So as we use our distance formula to find the length of this line, the distance between these points, it is d equals and we have x2 minus x1 squared plus y2 minus y1 squared.
00:46
And what these twos and ones mean are basically one is the first point and two is the second point.
00:52
So when you see x2, that means the x in the second point.
00:56
So this is the one here, this x value.
00:58
So you can do it either way, one and two.
01:01
It doesn't matter, but just so you designate one is one and the other is two.
01:04
So let's go ahead and use these points here.
01:06
X2 is the 1.
01:08
We'll do the square root of.
01:10
We have 1 minus and the x1 is the 1, the x in the first point.
01:15
So 4 squared.
01:17
Plus we'll do y2, which is 1 minus the y in the first point, which is 4.
01:25
Okay, so we're going to just subtract now.
01:27
And when we do that, we get 1 minus 4.
01:30
3 and 1 minus 4 that's negative 3 when we square both these they both should be the same so negative 3 squared is 9 so 9 plus 9 and that would be d equals the square root of 18 add those together we're going to hold on to this square root of 18 this is the length of one side ab and let's go ahead and check out another side we'll continue working here so let's do um bc so let's do bc here and the points for bcb is 1, negative 4, and c is negative 2, negative 2.
02:09
So let's just do that, negative 2, negative 2.
02:12
Okay, so once again, 0 .1, 0 .2 when we use the formula.
02:17
I'm not going to write the formula.
02:18
Again, it's right here, but we'll go ahead and put the values in here.
02:22
So let's do x2 minus x1.
02:25
So let's do negative 2 minus the 1 plus, and then let's do...
