Find the area of the regular polygon. Give the answer to the nearest tenth. decagon with a side of 4 cm

123.1 cm^2
129.4 cm ^2
246.2 cm ^2
139.8 cm ^2

Question

Find the area of the regular polygon. Give the answer to the nearest tenth. decagon with a side of 4 cm

123.1 cm^2
129.4 cm ^2
246.2 cm ^2
139.8 cm ^2

jdoe0001 · Answer

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how many degrees do you think each of the 6 sides will make in that hexagon?

highschoolmom2010 · Answer

no clue what does a  hexagon have to do with my question jw

jdoe0001 · Answer

hmmm ohhh..ahemm . it's a decagon lol,   I thought it was a hexagon hehe

highschoolmom2010 · Answer

lol understandable

highschoolmom2010 · Answer

thanks for trying

jdoe0001 · Answer

well... ahemm heheh

jdoe0001 · Answer

trying to make a quick graph  of the central angle =)

highschoolmom2010 · Answer

ok lol

highschoolmom2010 · Answer

anyone.....

jdoe0001 · Answer

heheh,darn it's taking longer than expected =)

rational · Answer

Area of regular polygon  = $\large     \frac{n}{4}\times s^2\cot(\frac{180}{n})$

jdoe0001 · Answer

hmmm

rational · Answer

for decagon $n = 10$
$s = 4$

plug into your calculator.

do you need a derivation for the formula ?

rational · Answer

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