00:01
So i have two similar triangles.
00:03
I'm going to call this one number one and i'll call this one number two.
00:09
And i have the area of the first which is 45 square centimeters and i have the area of the second and that's 80 square centimeters.
00:19
I'm going to let x equal the perimeter of one and y equal the perimeter of two.
00:27
Now i know that 45 over 80 is going to equal the perimeter of one squared over the perimeter of two squared.
00:37
So 45 over 80 equals x squared over y squared.
00:43
I also know that when i add my two perimeters the sum is 35.
00:49
So x plus y is 35 or y is 35 minus x.
00:56
So i'm going to take that value for y and bring it over here to my perimeter ratio.
01:05
That's x squared over 35 minus x quantity squared.
01:11
Now i'm going to multiply both cross multiply.
01:19
So i have 45 times 35 minus x squared equal to 80 squared.
01:27
I'm going to distribute this get rid of my parentheses and that's going to give me 45 times 35 is 1575 minus 45 x.
01:56
Now 1575 times 35 is 55125.
02:02
My outer terms are negative 1575...