SOLUTION: Given a side length of 18 inches, find the height of a stop sign rounded to the nearest tenth

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Question 1073740: Given a side length of 18 inches, find the height of a stop sign rounded to the nearest tenth
Answer by Fombitz(32388) About Me  (Show Source):
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H=18%2B2X
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The interior angles of the octagon are 135 degrees.
So the X-X-18 triangle is a 45-45-90 triangle so then,
X%5E2%2BX%5E2=18%5E2
2X%5E2=18%5E2
X=18%2Fsqrt%282%29
So,
H=18%2B36%2Fsqrt%282%29
H=18%2B18sqrt%282%29
H=18%281%2Bsqrt%282%29%29in