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AcidRa1nBest ResponseYou've already chosen the best response.0
Ok how does angle C equal 20 and PS is 5?
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Unkle it's not that hard come on...
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
there are 360° in a complete revolution, angle C is 1 eighteenth of the wayround \[\angle C=360°/18\]
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
wait what so how its it 20 on there?
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
did you simplify \(\angle C =\frac{360°}{18}=\dots\)
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
\[36=2\times18\] \[360=2 \times 18\times10\]
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
How would you find the area?
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
well the shape can be see as 18 of those little right angled triangle joined together, find the area of one then multiply by 18
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
dw:1338432746562:dw
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
I have a diferent problem on my notes.. Same shape but it says each side = 4
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
dw:1338433164896:dw
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
you can find length CS = a using a trigonometric function of the angle 20°
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Lets say the question only give you the length of one side is 4
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
How would you go about finding the area?
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
dw:1338432905847:dw
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
dw:1338433361442:dw
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Thats all it gives you. Find the area. I know it has something to do with finding the apothem and finding the perimeter and using the TAN function.
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Half of one side is 2.
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
\[\tan(20°)=\frac{\text{opposite}}{\text{adjacent}}=\frac5a\] \[a=\frac 5{\tan(20°)}\neq4\]
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
or is the 4 coming from a different problem/
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
the diagram posed at the top of the page does not have any side length equal to 4
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
4 from a different problem
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
OK, what is the new problem exactly/
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
What I drew that's all it gives me
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
A decagon with a side lengths of 4. Find the Area.
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
well the first one was a nonagon so the picture is wrong
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
RAWRRRRRRRRR I HATE MATH SO MUCH OMFG
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
dw:1338433609250:dw
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
I DONT HAVE TIME FOR THISSSS I WANNA SLEEP
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Yes now find the area. Just with that information.
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
well should i sing you a lullaby instead ?
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
ok so you might want to find the angle in triangle first, remember there are 360° in a revolution and i count 10 angles, so the angle in is \[360°/10\]
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
next find the length of the perpendicular , using the angle you just found and the tangent function
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
dw:1338433908040:dw, find the area of the triangle and lastly multiply this area by the number of those triangles in the decagon
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
360/10 =36? When I apply the TAN to 36 it's weird...
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
true, what did you determine as an approximation of length b
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
2 significant figures is probably fine
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
huh? I didnt get that far becuase I thought you need to know the TAN of 36
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
yeah \[\tan(36°)\approx0.727\]
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
\[\tan(36°)=\frac{\text{opp}}{\text{adj}}=\frac 2 b\] \[b=\frac {2}{\tan36°}\approx\cdots\]
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
why is it b= 2/tan36?
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
we are trying to find \(b\) so we can work out the are of the triangle \[\tan(36°)=\frac{\text{opp}}{\text{adj}}=\frac 2 b\] multiply both sides by \(b\) then divide both sides by \(\tan36°\)
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
yes \(b\approx 2.75\)
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
so then after we find the area which is 2.752 we take the perimeter which is 40, and do 1/2* 2.752* 40
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
find the area of this triangle dw:1338435087210:dw
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
\[A_{\triangle}=\frac{ab}2=\frac {2b}2=\cdots\]
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
you dont need the perimeter
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Maybe hes teaching it like that?
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
THe formula for Area is. 1/2 * Apothem * perimeter
 one year ago

UnkleRhaukusBest ResponseYou've already chosen the best response.1
whatever, my method is better ~ so the area of the small right angled triangle is 2.752 and there are 20 of these in the decagon the the total area is simply \(A_{decagon}=2.752\times20=\cdots\)
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Yeah lol same thing I got.
 one year ago

AcidRa1nBest ResponseYou've already chosen the best response.0
Well, thanks for taking like 30 minutes of your time to help me lol.
 one year ago
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