00:01
The perimeter of a triangle is five times the length of the shortest side.
00:06
Permitter equals five times the shortest side.
00:08
We're going to use s for shortest.
00:11
The length of the longer side is nine centimeters longer than the length of the shortest side.
00:16
So the shortest side plus nine equals the longest side.
00:21
The length of the middle side is four centimeters less than the length of the longest side.
00:26
The longest side minus four equals the middle side.
00:31
We're going to find the length of each of the sides.
00:33
Remember, perimeter is figured out by adding up all of the sides, s plus m plus l.
00:39
So let's use some substitution.
00:42
5s equals s plus m plus l, since both of those things represent perimeter.
00:50
We're going to continue using substitution.
00:53
We get s plus m is l minus 4, plus l is s plus 9...