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OpenSessame
 2 years ago
Find the area of the regular polygon. Give the answer to the nearest tenth. Decagon with a side of 4 cm.
OpenSessame
 2 years 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
 2 years ago
Best ResponseYou've already chosen the best response.0Can you help please??

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

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

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

koymoi
 2 years 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
 2 years 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
 2 years 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
 2 years ago
Best ResponseYou've already chosen the best response.0okay so the angle would be 72?

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

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

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

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

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

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

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

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

koymoi
 2 years 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
 2 years ago
Best ResponseYou've already chosen the best response.0I meant the outside angles lol

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

OpenSessame
 2 years 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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