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 one year ago
Find the area of the regular polygon. Give the answer to the nearest tenth. Decagon with a side of 4 cm.
 one year ago
Find the area of the regular polygon. Give the answer to the nearest tenth. Decagon with a side of 4 cm.

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OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0Can you help please??

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0@koymoi can you help?

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0I know the answer i just dont get how to get there.

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4do you know how many sides a decagon has

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4yes, now how many triangles of the same shape can we get from a decagon? I will give you lil bit hint in the pic below:

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4ok, now what we need to do is to figure out how to work out the area of one of those little triangle.

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4to do that, we need to get each inner angle of the decagon first. use this formula: 180(n2)÷n n=sides in this case, since decagon has 10 sides, so n=10

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0okay so the angle would be 72?

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0Uhm...Its the same length on both sides...right?

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0dw:1376884123072:dw

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0Wouldnt you need to know the interior angle though?

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0Wait its regular so all of them are the same!

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4that triangle is isosceles triangle, not equilateral triangle

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0But its a regular decagon...

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0dw:1376884408466:dw

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0dw:1376884457513:dw

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4yes thats why its isosceles. the only way to make it equilateral is when all the interior angles equals to 60 degrees.

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0I meant the outside angles lol

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4and since we have 10 of them triangles, so you just multiply by 10 to get the area of the decagon.

koymoi
 one year ago
Best ResponseYou've already chosen the best response.4and dont forget to round it to the nearest tenth

OpenSessame
 one year ago
Best ResponseYou've already chosen the best response.0I think i get it now since i know the final answer. THANKS:)
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