SOLUTION: :Given the points A(0,0),B(4,3) and C(2,9). what is the measure of /_ ABC?

Algebra ->  Trigonometry-basics -> SOLUTION: :Given the points A(0,0),B(4,3) and C(2,9). what is the measure of /_ ABC?      Log On


   

Question 356335: :Given the points A(0,0),B(4,3) and C(2,9). what is the measure of /_ ABC?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Since A is the vertex the angle should be BAC or CAB.
.
.
.

.
.
.
Let calculate the angle CAX and BAX make with the x-axis.
The angle CAB is then the difference.
tan%28CAX%29=9%2F2
CAX=77.5degrees
.
.
tan%28BAX%29=3%2F4
BAX=36.9degrees
.
.
CAB=77.5-36.9
highlight%28CAB=40.6%29degrees
.
.
.
If you really were looking for ABC, then

Define a new point D and calculate the angles ABD and DBC.
ABD%2BDBC=ABC
tan%28ABD%29=3%2F4
ABD=36.9degrees
.
.
.
tan%28DBC%29=6%2F2
DBC=71.6degrees
.
.
.
highlight%28ABC=36.9%2B71.6=108.5%29degrees