Ariyon D.

asked • 09/01/19

A regular octagon rests on one of the flat sides and has a total height of 10 ft. What is the measure of one of the octagon’s sides?

i have to use a method that is similar which is : Find the measure of one base angle.

   central angle = 360/9 = 40

   2 * side angle + central angle = 180

   2 * side angle + 40 = 180

   2 * side angle = 140

   side angle = 70°

Use a trig ratio to find the height of one triangle.

   tan(70°) = h/(8/2)

   h = 4*tan(70°)

   h = 10.99 in

Use A = 1/2 bh to find the area of one triangle.

   A = 1/2 (8)(10.99)

   A = 43.96 in2

Find the area of the entire polygon.

   A = 43.96*9

   A = 395.64 in2

 


1 Expert Answer

By:

Paul M. answered • 09/01/19

Tutor
5.0 (39)

BS Mathematics, MD

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