00:01
So for part one, a quarter circle, you have an area, a1, so this is equal to 1 fourth pi, r squared, is equal to 1 fourth pi times 2 .4 squared.
01:14
Then our x -centroid, x1, is equal to 4r, divided into 3 pi.
01:53
S equal to 4 times 2 .4 divided into 3 pi.
02:21
Then y centroid, which is y1.
02:46
So that's 4r divided into 3 pi, which equates to 4 times 2 .4 divided into 3 pi.
03:18
Then for, i'll call this 1, then 2, so this is area, a2, so start in the negative range.
03:55
So that's negative 1 half times pi times r squared.
04:09
It's equal to negative quantity 1 half times pi, 2 .4 squared.
04:24
They're x -centroid.
04:44
So we have x2.
04:48
I'll write that like x2, is equal to 0, 0 and that's by symmetry then or y centroid y2 is equal to 4r divided into 3 pi which equates to 4 times 2 .4 divided into 3 pi...