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## Answers

now

2sinx* cosx=sin2x

so

lhs=(2*sin20*cos20)*cos40*cos60*cos80/2sin20

=(sin40*2*cos40)*cos60*cos80/4sin20

=(sin80*c0s80*2)*cos60/8sin20

=sin160/16sin20 (cos60=1/2)

=sin(180-20)/16sin20

=sin20/16sin20

=1/16

so

lhs=rhs