Question 1071593
This octagon is made of 8 isosceles triangles each of two sides 8 inches and the tip angle of 45 degrees.  This makes the other two angles 67.5 degrees each.  You can use Law of Cosines to find the length of the side opposite of the tip angle.

Note that the tip angle between each of the two equal sides of the triangle is also a central angle of the circle.


Two sides known, 8 and 8; third side to be found, s;
{{{8^2+8^2-2*8*8*cos(45)=s^2}}}







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not absolutely the only way