What is the area of a regular octagon with a side of 6 cm?
A 178.06 sq cm
B 122.5 sq cm
C 216 sq cm
D 23 cm^2
E 173.82 cm^2
F 510 cm^2
2007-10-18 05:11:56 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
b
2007-10-18 05:16:33 · answer #1 · answered by kyle f 2 · 0⤊ 0⤋
This would inscribe into a square, 12cm on a side. That square would have area 12 x 12 = 144. The octagon has the four corners cut of, so it would be somewhat less, but more than half, so, B. 122.5 sq cm.
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KrazyKyngeKorny(Krazy, not stupid)
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2007-10-18 05:22:15 · answer #2 · answered by krazykyngekorny 4 · 0⤊ 0⤋
a = apothem = 3/tan(22.5) = 7.242641
P = perimeter = 8*6=48
A= aP/2 = 173.82 sq cm
2007-10-18 05:26:48 · answer #3 · answered by ironduke8159 7 · 0⤊ 0⤋
Answer is E
2007-10-18 05:35:47 · answer #4 · answered by kukgenius 2 · 0⤊ 0⤋
b
2007-10-18 05:24:33 · answer #5 · answered by Heroz 2 · 0⤊ 0⤋