#idk how to do this geometry question

46 messages · Page 1 of 1 (latest)

acoustic socket
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please help

outer mantleBOT
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acoustic socket
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im new to the topic (its about cosine and sine law)

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and also the applications of different trig methods.

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im just a little lost on this question.

modest violet
acoustic socket
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then what tho

modest violet
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did you get that far

acoustic socket
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i somehow got smth like 44.2 but the book says 34.2

acoustic socket
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is it possible to help calculate it or smth? idk. prolly a brain malfunction on my part.

modest violet
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book is correct

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what steps do you have

acoustic socket
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well basically cuz angle EDC is 50, CD is 10

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don't i use sine law to prove that angle CED is like 106.xx

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cuz it's obtuse?

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then you can find angle ECA = 90-(180-106.xx-50 )

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then use cos law to find AE

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and then sin law to find CAE and thus EAB

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then use the area = 1/2 ab sinC

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to solve the area.

acoustic socket
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i just can't seem to figure out which step was the wrong one...

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i know im wrong,i just dunno where it started...

modest violet
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this is definitely a bit overcomplicated

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once you have <ECD = 180 - 106.xx - 50

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drop perpendicular from E onto CD
say it reaches CD at point F
then <CFE has a right angle at F, by definition
and so you can find EF
then height of triangle AEB will be 10 - EF

acoustic socket
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oh

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OH

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wait but how do u solve for EF

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?

modest violet
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because EF/CE is sin(<ECF) = sin(<ECD)

acoustic socket
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sorry im new to this chapter, and i kinda suck at geometry....

modest violet
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opposite over hypotenuse

acoustic socket
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ah

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gotcha

modest violet
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i think you will find creating right triangles even when diagram does not have them is quite helpful

acoustic socket
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oic

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wow

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i've just successfully wasted 30 minutes of my life

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trying to solve this lol

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thanks 🙂

modest violet
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np

faint mountainBOT
acoustic socket
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+close