The perimeter of a regular hexagon is 48 inches. What is the number of square inches in the positive difference between the areas of the circumscribed and the inscribed circles of the hexagon? Express your answer in terms of pi.

1 Answer
Aug 5, 2018

Diff. in area between Circumscribed and Inscribed circles

Ad=πR2πr2=36π27π=9π sq inch

Explanation:

Perimeter of regular hexagon P=48inch

Side of hexagon a=P6=486=6 inch

Regular hexagon consists of 6 equilateral triangles of side a each.

![http://www.oocities.org/web_sketches/calculators/regular_polygon/regular_polygon_layout.html](useruploads.socratic.org)

Inscribed circle : Radius r=a2tanθ,θ=602=30

r=62tan(30)=62(13)=33 inch

Area of inscribed circle Ar=πr2=π(33)2=27π sq inch

![http://davechessgames.blogspot.com/2011/01/mathematical-problems-3dhttp://-pi-from.html](https://useruploads.socratic.org/C10luMItRGi1ydPSkEqa_inscribed%20hexagon.jpg)

Radius of circumscribed circle R=a=6 inch

Area of circumscribed circle AR=πR2=π62=36π sq inch

Diff. in area between Circumscribed and Inscribed circles

Ad=πR2πr2=36π27π=9π sq inch