I've been trying to figure out how to solve this problem for a while, but I just don't get it.... Can somebody explain to me how I would go about Finding Angle A In triangle ABC if c= 19, a= 17, and b=14.... I don't need and answer I need an explanation....
2006-08-29 18:15:07 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Yes, use the law of cosines. a²=c²+b²-2cb cos A, thus A=arccos ((c²+b²-a²)/(2cb)).
2006-08-29 18:26:01 · answer #1 · answered by Pascal 7 · 0⤊ 0⤋
In my geometry class, triangles' interior angles added up to 180 degrees. So the explanation is that this is some new measuring system for triangles, so further explanation is impossible.
2006-08-29 18:20:36 · answer #2 · answered by Tekguy 3 · 0⤊ 0⤋
draw out the triangle. then label it then try to label triangle .cross multiply the labels on tyeh triangles to the opposite side ex"if c=19, then the opposite would be C. label it and find your A. then as you know, you will draw a line from pt. C to c=19. that will give you your 3rd side of the inside triangle.now use your pythagorean. i hope that i somehow helped.best of luck.
2006-08-29 18:43:21 · answer #3 · answered by icycrissy27blue 5 · 0⤊ 0⤋
pythagorean thereom is a squared+b squared=c squared for a triangle containing a right angle. which yours is not. yours seems to be an isocoles triangle which brings in the theory of complementary angles.if you can't figure it out geometrically then try it algebraically. youshould have had this in school last year.
2006-08-29 18:25:10 · answer #4 · answered by km7574 2 · 0⤊ 0⤋
a^2 = c^2 + b^2 - 2cb*cos(A), law of cosines
Please note, you can't use the Law of Sines because you need to know at least one angle.
c=19, a=17, b=14
substituting yields cos(A) = .503, A = cos^-1(.503) = 59.8 degrees
2006-08-29 18:46:12 · answer #5 · answered by mcfallsg 1 · 0⤊ 0⤋
There is formula:
a^2=b^2+c^2-2bcCos(teta)
Where teta is the angle between b and c.
This formula is correct for any type of triangle. You can solve it for teta.
2006-08-29 18:24:19 · answer #6 · answered by Farshad 2 · 0⤊ 0⤋
Law of sines...without having to type it up too much for you I took the liberty of finding it for you on wikipedia. it has all the information that you'll need to complete the problem.
2006-08-29 18:32:44 · answer #7 · answered by Aaron 2 · 0⤊ 0⤋
use the law of cosines
try this page:
http://hyperphysics.phy-astr.gsu.edu/hbase/lcos.html
or if you don't want to use law of cosines you can check this out:
http://mathforum.org/library/drmath/view/53931.html
2006-08-29 18:28:40 · answer #8 · answered by Deep Thought 5 · 0⤊ 0⤋
type of triangle?
2006-08-29 18:17:29 · answer #9 · answered by janmarbol 3 · 0⤊ 1⤋