00:01
So we have in figure abc three points in a horizontal field, and it says that a is due west of b.
00:06
So here's b, and a has to be due west.
00:10
And we know that the bearing of b from c, so had to have from c, is 125 degrees.
00:20
So this angle from north has to be 125 degrees.
00:26
And so that is going to end up being angle b is down here and we know that this little angle right here this is 90 degrees and then plus 35 degrees so this angle must be 35 degrees and we want to find in part a we want to find first of all what the distance is from a to c so we want to find how long that is and we we have a side angle side, so we can use law of cosines.
00:58
So ac squared will equal that 460 squared plus the 430 squared minus 2 times 460 times 430 times the cosine of the included angle, which is 35 degrees.
01:16
Now we have to make sure that the calculator is in degree mode.
01:19
Mine is.
01:20
So we have that 460 squared plus 430 squared minus 2 times 460 times 430 times the cosine of 35 degrees.
01:35
And then we'll square root that answer to find that that side ac is a length of 269 .15, and that would be in meters.
01:47
Now on part 2, it says angle acb.
01:56
We want to find that apparently...