Question

PLEAASSSSE HELP!!!!
1!!!!!!!!!!!!!!!!!!!!!!

Suppose a triangle has sides a b c, and let theta be the angle opposite the side length a. if cos theta>0, what must be true

a) a^2+b^2=c^2
b)a^2+b^2>c^2
c) b^2+c^2>a^2
d)b^2+c^2 12 years ago

Answer 1

We have a law of cosines which says
cos A = (b^2 + c^2 - a^2)/2bc
cos B = (a^2 + c^2 - b^2)/2ac
cos C = (a^2 + b^2 - c^2)/2ab

where A,B,C are angles opp. to sides a,b and c
so your ques.
cos theta >0
(a^2 + c^2 - b^2)/2ac > 0
solving you'll get a^2 + c^2 > b^2
its b

Answer 2

thank u so much i hope this is right!!!:)

Answer 3

k : )