Answer:
Explanation:
they give you this formula just above the question:
Law of cosines: c= sq rt [ a^2+b^2﹣2a*b*cos(γ)]
EF = ??? :/ what is it ?
opp = 26
adj = 11
D = 108 °
where opp = a, adj = b , cos (y ) = cos (108) :P c = EF , nice !
then
EF = sq rt [ 26^2 + 11^2 - 2*26*11*cos(108) ]
EF = sq rt [ 676 + 121 - 572 * (-0.30901699) ]
EF = sq rt [ 797 + 176.7577208 ]
EF = sq rt [ 973.7577208 ]
EF = 31.205
rounded to nearest 10th is
EF = 31.2
:)
FYI, I made two big mistakes figuring this out. one I subtracted the 176 from the 797 but it's a double negative.. so I got that figured out. then I put in 30 instead of 31 as the answer.. soooo, I'm confident in the answer now, but it's just easy to make mistakes on these. :/