Help w/ Trig Questions? #1

Hi, here are just two questions. I know you like to answer them as separate but there are way too many. Please show your work and make a picture to help!
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2 Answers
Mar 17, 2018

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In the #DeltaABC # to be drawn

#AB=12m,BC=10mand angle BAC=40^@#

So length of the perpendicular #BN# drawn from #B# on #AC# will be given by

#BN=ABsinangleBAC=12xxsin40~~7.71m#

But #BC=10m#

So #BC > BN and BC < AB #

So in constructing #DeltaABC# the arc of radius #10m #drawn centering #B# will intersect at two different positions (C) giving two lengths of #AC=x# and forming of two triangles becomes possible.

Mar 17, 2018

2nd part
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By the problem

In #DeltaAPB#

#PA=16.2km,PB=18.9kmandangleAPB=53^@#

So applying cosine law we can write,the distance between the ruders

#AB=sqrt(PA^2+PB^2-2PAxxPBcosangleAPB)#

#=>AB=sqrt(16.2^2+18.9^2-2xx16.2xx18.9xxcos53^@)#

#~~15.8km#