A wooden plank is leaning against a wall. The bottom of the plank is 3 feet from the wall. Answer each of the following questions, and show all of your work. Find AC,approximate length of the...

A wooden plank is leaning against a wall. The bottom of the plank is 3 feet from the wall. Answer each of the following questions, and show all of your work. Find AC,approximate length of the plank to nearset tenth of a foot. Find BC the height off the ground where board touches the wall to the nearest foot/ Angle is 49 degrees at acute angle at C 3 feet is at AB it is either cos49 or sin49 Thank you for your help

Asked on by sheriff97

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crmhaske | College Teacher | (Level 3) Associate Educator

Posted on

Does this look like your diagram?

In which case:

`sin49=(opp.)/(hyp.)=3/L-gtL=3/sin49~~4`

`tan49=(opp.)/(adj.)=3/h-gth=3/tan49=2.6`

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sheriff97 | Student, Grade 9 | (Level 1) Honors

Posted on

Yes, that is my diagram exactly .... Thank you very much for your help.  A++

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crmhaske | College Teacher | (Level 3) Associate Educator

Posted on

No problem.  I apologize for the original confusion.

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Seema Adiga | High School Teacher | (Level 2) Adjunct Educator

Posted on

By representing the data in the right triangle ABC we get

AC=  height of the plank = l

BC = height of the ground where the plank touches the wall = h

AB = distance from the wall = 3

so, tan 49 = AB/BC = 3/h = 3/1.1504 = 2.6f

     sin 49 = AB / AC = 3/ l = 3/0.7547 = 3.9f

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